Here - Eco-Ideal Consulting Sdn Bhd

Sarawak Government/DANCED 

Sustainable Urban Development Project, Sarawak 

ENVIRONMENT OF 

SG. SARAWAK: 

RELATIONSHIPS 

BETWEEN CITY AND RIVER 

nreb State 

Government 

Danced

ENVIRONMENT OF 

SG. SARAWAK: 

RELATIONSHIPS 

BETWEEN CITY AND RIVER 

River Quality Baseline Study, Volume 1: 

Main Report. 

Existing River Quality, 

Pollution Sources & Environmental Management of Sg. Sarawak 

COWI Danwaste

Environment of Sg. Sarawak - 

Relationships Between City and River 

Prepared by Erling Povlsen, COWI A/S 

with 

Local Consultants 

Chemsain Konsultant Sdn. Bhd. 

Daya Rancang 

1 st Edition (1 st Print) 

September 2001 

Copies: 400 

The Authors and Danced Copenhagen 

Quotations permitted with source credit 

Printed by UM Colour Printing Company 

Report No. SUD-02-25

ISBN 983-40546-5-3

DANCED SARAWAK GOVERNMENT 

Sustainable Urban Development Project 

Natural Resources and Environment Board 

River Quality Baseline Study 

Volume 1 

Main Report 

Existing River Quality, Pollution 

Sources and Environmental 

Management of Sg. Sarawak 

Final 


NREB 

Natural Resources and 

Environment Board 

DANCED 

Danish Cooperation for 

Environment and Development

Report no. SUD-02-25 

Issue no. 02 

Date of issue 4 September 2001 

DANCED SARAWAK GOVERNMENT 

Sustainable Urban Development Project 


River Quality Baseline Study Volume 

1 

Main Report 

Existing River Quality, Pollution 

Sources and Environmental 

Management of Sg. Sarawak 

Final 


Prepared ERP, HBJ, Chemsain, Daya Rancang 

Checked ILA 

Approved ILA

River Quality Baseline Study. Vol. 1 

Table of Contents 

1 Summary 4 

2 Introduction 13 

2.1 Background 13 

2.2 River Quality Baseline Study 14 

3 Data Compilation 18 

3.1 Compilation of Existing Data 18 

3.2 Supplementary Field and Desk Studies 19 

3.3 Assessment of Collected Data 19 

4 Background Conditions 21 

4.1 River and Catchment areas 21 

4.2 Physical Background Conditions 25 

4.3 River Ecosystem 28 

4.4 Landuse 32 

4.5 River Quality Management in Kuching 39 

5 River Quality 43 

5.1 Potential Impacts of the Discharge of Wastewater 43 

5.2 Surface Water Quality 46 

5.3 Sediment Quality 60 

5.4 Accumulation of Pollutants in Organisms 76 

5.5 Ecosystem Impacts 77 

5.6 Floating Debris 81 

6 Sources of Pollution and Pollution load 83 

6.1 Overview of Pollution Sources 83 

6.2 Pollution from Households 84 

6.3 Pollution from Food Outlets 91 

6.4 Pollution from Industries 95 

6.5 Pollution from Agriculture 100 

6.6 Other Sources of Pollution 103 

6.7 Other Sources of River Quality Deterioration 106 

C:\Documents and Settings\user\Desktop\SUD-02-25 - River quality baseline study Vol.1 by Erling\final\River Quality Baseline main report.doc 

1


7 Discussion and Conclusion 108 

7.1 Degree of Pollution 108 

7.2 Sources 108 

7.3 Existing Technical Measures to Reduce Pollution Loading 115 

7.4 Existing Control and Enforcement Measures 116 

7.5 Assessment of Preliminary Indicators 116 

8 References 121 

Appendix 1. Data on surface Water Quality 1999 and 2000 

Appendix 2. An Overview of the State Administration 

Appendix 3. A summary of Relevant Activities and Mandates 


2


Abbreviations 

Amm-N Ammoniacal Nitrogen 

As Arsenic 

BOD Biochemical Oxygen Demand 

Cd Cadmium 

Cl Chlorine 

CBD Central Business District 

COD Chemical Oxygen Demand 

Cr Chromium 

Cu Copper 

DBKU Dewan Bandaraya Kuching Utara (Kuching North City Hall) 

DID Department of Irrigation and Drainage 

DO Dissolved Oxygen 

DOE Department of Environment 

EMS Environmental Management System 

EMT Environmental Management Team 

EQA Environmental Quality Act 

Fe Iron 

Hg Mercury 

INWQS Interim water quality standard 

JKR Jabalan Karja Raya (Department of Public works) 

KBM Kuching Barrage Management Sdn Bhd 

KWB Kuching Water Board 

L & S Land and Survey Department 

LSI Large Scale Industries 

MBKS Majlis Bandaraya Kuching Selatan (Kuching City South Council) 

MID Ministry of Industrial Development 

Mn Manganese 

MPP Majlis Perbandaran Padawan (Padawan Municipal Council) 

NO3-N Nitrate – Nitrogen 

NREB Natural Resources and Environment Board 

O & G Oil and Grease 

PAH Polyaromatic Hydrocarbon 

Pb Lead 

Sg. Sungai (River) 

SHD State Health Department 

SMI Small-Medium Industries 

SPU State Planning Unit 

SRB Sarawak Rivers Board 

SUD Sustainable Urban Development 

Tot-N Total Nitrogen 

Tot-P Total Phosphorous 

TPH Total Petroleum Hydrogen 

TSS Total Suspended Solids 

UNIMAS University of Malaysia Sarawak 

Zn Zinc 


3


1 Summary 

A baseline study of the river quality of Sg. Sarawak and tributaries has been 

carried out in connection with the development of an Environmental Management 

System (EMS) for Kuching. The objective of the baseline study is to provide 

a description of the river quality and sources of pollution with a view to 

make it possible to set realistic goals and indicators for the future river quality 

in the EMS. 

The report describes: 

The background conditions necessary for the interpretation of river quality 

data (climate, geology, hydrography, river bed sediments, flora, fauna, river 

ecosystems and landuse); 

The present river quality in terms of surface water quality, sediment quality 

and ecosystem impacts of pollution; 

The existing sources of pollution and the load from these; and 

The recommendations for revision of preliminary indicators based on results 

of the baseline study. 

The report will be used as a basis for the specifications of formats for the EMS, 

in terms of River Quality. The major findings are summarised below. 

THE SG. SARAWAK RIVER SYSTEM 

Sg. Sarawak has two principal tributaries namely Sg. Sarawak Kiri and Sg. Sarawak 

Kanan, rising in the mountain ranges to the south of Kuching at the border 

to Indonesia. The two tributaries meet near Batu Kitang, some 34 km upstream 

of Kuching. From Batu Kitang the mainstream Sg. Sarawak meanders 

across a wide coastal flood plain and through the city of Kuching. Downstream 

of Pending, the industrial area in the eastern part of the city of Kuching, Sg. 

Sarawak confluence with Sg. Kuap and further downstream by Loba Batu Belat 

at further downstream before discharging to the South China Sea at Muara Tebas. 

In Kuching City, several small tributaries discharge to Sg. Sarawak including 

Sg. Maong, Sg. Bintangor, Sg. Padungan Sg. Sekama, Sg. Bintawa and Sg. 

Biawak. 


4


A total of 21 drainage sub-catchement areas in Kuching are discharging into the 

part of Sg. Sarawak, which is flowing through Kuching. The remaining part of 

the city, including the Sama Jaya Free Industrial Zone drains to Sg. Kuap. 

In 1997, a gated barrage was constructed through the Sejingkat Isthmus and the 

river was blocked by causeways at Jalan Keruing and Jalan Bako in order to 

regulate the tidal influence on the river. 

RIVER QUALITY 

The present river quality has been assessed in terms of: 

Surface water quality 

River Sediment quality 

Pollutants in organisms 

Ecosystem impacts 

General 

The baseline study has documented that the tributaries of Sg. Sarawak situated 

in Kuching City and the part of Sg. Sarawak, which is flowing through 

Kuching, is significantly polluted. 

The major issues are serious pollution with faecal derived coliform bacteria, 

which is posing a health risk and pollution with organic matters and nutrients, 

leading to oxygen deficiency, deleterious impact on bottom fauna and offensive 

odours. The main source of the pollution is raw and insufficiently treated sewage 

and wastewater, which is discharged to the open drains in the city. 


The water quality of different zones of the entire river system have been classified 

according to the Malaysian Interim National Water Quality Standards 

(INWQS). A summary of the results of the classification is presented in Table 

1.1. 

The water quality in the tributaries Sg. Maong, Sg. Bintangor, Sg. Padungan 

Sg. Sekama and Sg. Tabuan in the city is very poor and falls between the class 

IV and class V of the INWQS. Very high concentrations of BOD and ammoniacal 

nitrogen and very poor oxygen conditions are encountered. The concentrations 

of oxygen are in fact so low that only very few organisms, if any can 

survive in the water (i.e. concentrations consistently below 2 mg/l). The content 

of faecal derived bacteria is extremely high and the water poses a health risk. 


5


Table 1.1 Summary of INWQS classification of the different zones of the Sg. 

Sarawak system. 

Zone INWQS 

Physical-chemical 

parameters 

Zone A (Sg. Sarawak Kanan) IIA/IIB 

Zone B (Sg. Sarawak Kiri) IIA/IIB 

Zone C (Sg. Sarawak Proper from Batu 

Kawa to upstream Satok bridge) 

Zone D (Sg. Sarawak Proper from Satok 

Bridge to downstream of barrage) 


INWQS 

Bacteriological parameters 

IIA/IIB III 

III V 

Zone E (Sg. Maong) IV/V V 

Zone F (Sg. Bintangor) IV/V V 

Zone G (Sg. Padungan) IV/V V 

Zone H (Sg. Sekama) IV/V V 

Zone I (Sg. Tabuan) IV/V V 

The water quality in the stretch of the Sg. Sarawak Proper, which is running 

through Kuching, is better than in the tributaries but relatively low concentrations 

of oxygen and somewhat elevated concentrations of NH4-N are encountered. 

The water can be classified as Class III in terms of physico-chemical parameters. 

However, in terms of bacteriological parameters, the water is only 

Class V. 

The water quality in Sg. Sarawak upstream of Kuching, including Sg. Sarawak 

Kiri and Kanan is quite good and generally complies with class IIA/IIB in 

terms of physico-chemical parameters. However, the water does not meet the 

class IIB standards for faecal derived bacteria. 

There is no or very little odour in the water of Sg. Sarawak Proper. In contrast, 

the water in the tributaries such as Sg. Bintangor and Sg. Sekama as well as 

some drains is quite smelly. 

The levels of heavy metals in water are generally very low and below the detection 

limits even in the very polluted tributaries. 

The concentrations of iron and manganese are generally high and violating the 

INWQS standards. The high iron and manganese concentrations are not primarily 

due to human activities. The presence of high concentrations of iron and 

manganese in surface water are common in tropical natural waters, especially in 

swampy areas. Here, the anaerobic conditions in soils induce the mobilisation 

of insoluble iron compounds to soluble iron due to chemical reduction processes. 

Manganese reacts the same way as iron. 

The concentrations of agrochemical and pesticides are generally below detection 

limits in surface water samples. 

6


Sediment Quality 

Organic matter and heavy metals from outlets in Kuching are clearly accumulated 

in the sediments of Sg. Sarawak. This results in elevated loss on ignition 

and elevated concentrations of Tot N, Tot P, NH4-N, Pb, Cu, Ni, Cd, Cr, As and 

Zn along the stretch of the river from downstream of the confluence of Sg. 

Maong and Sg. Sarawak to the area off Kuching Port Authority. 

The concentrations of pollutant decrease further downstream around Pending; 

probably due to the flushing procedure at the barrage. If the flushing were not 

carried out it is expected that elevated concentrations of pollutants would also 

be encountered in this area. 

The concentrations of heavy metals, except Hg, are well below potentially toxic 

levels. Hg is found in concentrations, which is potentially toxic to sensitive organisms 

according to recently developed Canadian Sediment Quality Criteria. 

The major source of Hg is not from the city as potentially toxic levels are already 

encountered at the upstream of Kuching. The possible source may be 

from previous mining activities between Bau and Buso. 

Metals originated from the previous gold mining activities and perhaps quarry 

operations in the area between Bau and Buso have resulted in elevated concentrations 

of heavy metals significantly in the sediments of Sg. Sarawak Kanan. 

Very high and toxic concentrations of As and Hg have been encountered. Quite 

high concentrations of Cd, Cr and Pb have also been found. 

The concentrations of heavy metals in Sg. Maong are higher than those found 

in Sg. Sarawak and potentially toxic levels of Cd, Pb and Zn are encountered. 

Heavy metals from the Sama Jaya Free industrial Zone are accumulated in the 

sediments of Sg. Kuap. The concentrations of heavy metals (Cu, Pb, Ni, Cr, Cd 

and Zn) increase markedly from upstream of the industrial estate to the areas 

off and downstream of the estate. Although heavy metals are accumulated in 

the sediments, the concentrations are below levels, which are likely toxic to 

aquatic organisms. 

Pesticides and Polyaromatic Hydrocarbons (PAH) are not found in the sediments 

at the studied sites in Sg. Sarawak and Sg. Kuap. Elevated concentrations 

of total hydrocarbons were encountered at Satok Bridge and off Sg. Bintawa. 

Pollutants in organisms 

Freshwater molluscs living in the contaminated sediments between Buso and 

Bau have accumulated Cu and Zn to levels, which could pose a risk to consumers. 

The levels of As are also considerably high. There are no data from the part 

of the river running through Kuching. 

Ecosystem impacts 

The high load of organic matter from Kuching clearly affects the benthic fauna 

in Sg. Sarawak. 


7


At some sites, the organic load is apparently so high and the supply of oxygen 

from exchange of oxygen rich water so low that poor oxygen conditions in 

sediments results in the decrease in density (abundance) and number of species. 

This seems to be the case downstream of the confluence to Sg. Maong and at 

the Satok Bridge. 

Off Sg. Bintagor and off Kuching Port Authority high organic loads apparently 

results in a significantly increased abundance and number of species, the reason 

probably because of the organic matter constitute an increased amount of food 

without being so high as to cause oxygen depletion. 

SOURCES OF POLLUTION AND POLLUTION LOAD 

The poor water quality in the tributaries and the part of Sg. Sarawak traversing 

through Kuching is clearly due to the discharge of untreated sewage from the 

drains in the city. 

Estimation of pollution loads to Sg. Sarawak from households, food outlets and 

industries has been carried out in order to identify the source of the most severe 

pollution of Sg. Sarawak in Kuching City. The estimations include loads from 

the sub-catchment areas discharging to Sg. Sarawak from (and including) Sg. 

Maong to the causeway east of Pending. The areas discharging to Sg. Tabuan 

and Sg. Kuap are not included in the estimates. 

In general, untreated sewage from households is identified as the most significant 

source of pollution as a whole. The loads of BOD, COD, TSS, Tot-N, Tot- 

P and oil and grease from households are orders of magnitude larger than the 

loads from food outlets (markets, food centres, restaurants etc.), industries and 

other sources (Table 1.2). 

However, food outlets (restaurants, markets etc.) are the significant local source 

of pollution in the Central Business Centre immediately south of Sg. Sarawak. 

In sub-catchment areas Bintangor 2, Bintangor 3, Padungan, Periok and Biawak, 

20-40% of the BOD load and as much as 71-83% of the load of oil & 

grease are discharged from food outlets. In Sekama and Bintawa, 83 and 71% 

of the oil and grease is from food outlets. Presently, the Local Councils actually 

spend huge resources in cleaning the oil and grease in the drains downstream 

due to the inadequate treatment facilities. 

The most significant load of organic pollution is at the Maong sub-catchment 

area, followed by Padungan, Bintawa1 and Seman Lama. The highest loads of 

heavy metals are encountered in the Pending area (Sekama 1, Periok, Biawak, 

Bintawa, Bintawa 1), Padungan and Maong. 

The total load of BOD from the Sg. Kuap catchment (not included in the estimates 

above) has been roughly estimated at 3,000-4,500 kg/day, which is the 

same magnitude as the discharge from the Sg. Maong catchment. 

Pig farm located at the upstream of Kuching is also one of the significant 

sources of pollution to Sg. Sarawak. 


8


Table 1.2 Estimated loads of pollutants to Sg. Sarawak and tributaries from 

different types of sources in Kuching. (Rounded figures). 

Households Food outlets 

(Markets, Food 

centres, Restau- 

rants etc) 


Industries Other 

BOD kg/day 5900-9700 650 15 50 

COD kg/day 19900-26000 800 40 90 

TSS kg/day 5400-8000 260 60 40 

Tot-N kg/day 2600-3400 30 5 2 

Tot-P kg/day 500-600 10 3 2 

Oil & grease kg/day 200-350 60 2 2 

Pb kg/day - - 0.02 - 

Cd kg/day - - 0.002 - 

Cu kg/day - - 0.01 - 

Zn kg/day - - 0.7 - 

Fe kg/day - - 0.9 - 

Mn kg/day - - 0.07 - 

Al kg/day - - 0.9 - 

AOX kg/day - - 0.009 - 

STATE OF TECHNICAL MEASURES TO REDUCE POLLUTION 

The City of Kuching does not have a functional wastewater treatment system. 

Almost all houses in Kuching discharge untreated greywater directly to the 

stormwater drains in the city, which later drain into the tributaries (Sg. Maong, 

Sg. Bintangor, Sg. Padungan etc.) or directly to Sg. Sarawak. Consequently, the 

sewage from the houses does not comply with the standards, which are stipulated 

in the Environmental Quality (Sewage and Industrial Effluents) Regulations, 

1979. 

The houses are equipped with individual septic tanks, which receive the blackwater. 

Septic tanks are generally not very efficient. Only about 30 % of the organic 

matter and no nutrients are removed prior to discharge, even with the 

most efficient type of septic tanks. In addition, the septic tanks in Kuching are 

generally not functioning due to improper desludging. As a consequence, 

blackwater is discharged almost untreated to the drainage system. Untreated 

blackwater is undoubtedly the main source contributing to the extremely high 

levels of faecal coliforms in the tributaries and Sg. Sarawak Proper. 

The food outlets also generally discharge untreated wastewater directly to the 

drains although thereare some inefficient treatment facilities exist. At present, 

information on the number of food outlets with treatment facilities is not available. 

In general, the sewage from food outlets does not comply with the regulations 

of 1979. 

9


Many industries have their own wastewater treatment system. However, there 

are a few industries with or without inadequate systems. Presently, data on the 

number of industries with or without a proper wastewater treatment system are 

not available. 

In the SUD field study, it was observed that the industries equipped with proper 

treatment facilities complied with the regulations, whereas those without facilities 

or with inadequate facilities did not. 

The findings of this study clearly indicate that the water quality of the Sg. Sarawak 

and its tributaries could be improved by establishing efficient sewage 

treatment of sewage for households. 

The study has also shown that introduction of regular desludging of septic tank 

will not improve the water quality significantly. Estimates has indicated that 

even if all septic tanks in Kuching were desludged regularly and functioning 

properly, the effect in terms of reducing the load to the tributaries and The 

River still be insignificant. The discharge of BOD from blackwater will still be 

high and the discharge of nitrogen and phosphorous are not reduced at all. 

Introduction of proper treatment facilities at food outlets in the Central Business 

Centre at the south of Sg. Sarawak will also significantly improve the water 

quality locally. 

STATE OF CONTROL AND ENFORCEMENT MEASURES 

The enforcement measures are generally passive, i.e. only in case of complaints, 

authorities carry out inspections and may impose a fine to the offender. 

There is currently no specific active enforcement measure carried out by the 

authorities to control the sewage discharge from households and/or food outlets. 

Other than cleanliness campaigns and awareness programmes, no direct 

inspection or regular checks on the discharge has been made. 

The Department of Environment (DOE) is monitoring the wastewater from a 

small fraction of the industries in Kuching for compliance to the Environmental 

Quality Act, 1974 (EQA). The monitored industries include: industries discharging 

more than 60 m 3 wastewater per day or where the total load of BOD 

in effluents exceed 6 kg per day, industries involved in the processing of oil 

palm fruit and raw rubber. 

NREB is regulating the outlets from pig farms and other livestock. 

EFFECT OF THE BARRAGE 

Kuching Barrage Management is currently operating a flushing scheme to mitigate 

environmental impacts of the barrage. Potential impacts, which are mitigated 

by the flushing scheme, include: 

Reduction of saltwater intrusion and river flow velocity; 


10


Increase of sedimentation of suspended matter due to reduction of flow velocities; 

Increased risk of oxygen depletion and accumulation of organic material, 

nutrients and bacteria upstream of the barrage; 

Risk of impacts on mangroves and nipah forests due to the decreased salinity; 

Risk of reduction of the stock of the giant freshwater prawn which is an 

important commercial species, due to blocking of migration routes to and 

from spawning and nursery grounds downstream of the barrage; and 

Reduction of the population and catch of marine and brackish-water species 

fish in the river due to reduced salinity. 

Should the flushing scheme for some reason be inadequate in the future, there 

is a risk that measures to improve the water quality may be affected by the 

presence of the barrage. The interpretations of state indicators in the EMS 

should therefore always be related to the operation of the barrage. 

RECOMMENTATIONS IN TERMS OF EMS 

The baseline study has indicated that: 

Some of the selected preliminary indicators are not suitable as indicators; 

Some of the preliminary indicators should be modified; and 

Some new indicators should be added. 

An overview of the proposed modifications of the preliminary state indicators 

is presented in Table 1.3. Arguments for the proposals are discussed in section 

7.5. 

It is proposed that all preliminary load indicators be used in the EMS. In addition 

it is proposed, that estimates of loads from households, food outlets and 

industries be used, applying the methods used in the baseline study. 


11


Table 1.3 Overview of modifications of preliminary state indicators for the 

EMS for river quality. 

Surface water 

quality 

Sediment 

quality 

Pollutants in 

aquatic organ- 

isms 

Ecological 

(biological) 

parameters 

Preiminary indicators 

proposed to be included 

in EMS 

DO, pH, BOD, COD, 

TSS, Ammoniacal ni- 

trogen (NH 4-N), Nitrate 

(NO 3), Phosphate (P), 

Faecal coliforms, Total 

coliforms. 

Nutrients (NH 4-N, NO 3), 

Heavy metals (Hg, Pb, 

As, Zn, Cd, Cr, Cu, Ni, ) 

PAH, Total petroleum 

hydrocarbons 


As, Zn, Cd, Cr, Cu, Ni) 

Polyaromatic Hydrocar- 

bons, PAH, Total petro- 

leum hydrocarbons 

(TPH) in transplanted 

mollucs 

Diversity of benthic 

macroinvertebrates 

(Shannon Wiener). 

Cpu (catch per unit effort 

of giant prawn (Macro- 

brachium rosenbergii) 

and the fish species Mys- 

tus spp. and Oxyeleotris 

marmorata 

Aesthetics Volume of floatables 

collected from Sarawak 

River. 

Threshold odour number 

New indicators proposed 

to be added 

Loss on ignition 

Total N 

Total P 

Number of species, 

abundance (no individu- 

als/m²) and species com- 

position of benthic inver- 

tebrates 

Catch per unit effort of 

all fish and prawn spe- 

cies in a catch 

Number of complaints of 

smell in river, drains and 

tributaries 


Preliminary indicators 

proposed to be excluded 

from the EMS 


As, Zn, Cd, Cr, Cu, Ni, 

Fe, Mn) 

PAH, Total petroleum 

hydrocarbons 

Fe, Ni 

Invertebrates of zz 

family 

12


2 Introduction 

2.1 Background 

In June 1999, the State Government of Sarawak initiated the Sustainable Urban 

Development Project in collaboration with the Danish Cooperation on Environment 

and Development (DANCED). 

The purpose of the project is to develop and implement an Environmental 

Management System (EMS) for the City of Kuching within two areas of concerns; 

namely river water quality and waste management. 

The project has elaborated a generic model for a coherent EMS, which will 

form the basis for developing a concrete EMS, adapted to the local Kuching 

context. 

An important part of the SUD Project is the elaboration of a baseline study on 

river quality and river quality management of Sg. Sarawak and its tributaries. 

The baseline study is carried out as a first step in the implementation of the 

concrete Environmental Management System for the River Quality for the 

Kuching City. The objective of the baseline study is to be able to set realistic 

goals and indicators for the future river quality. 

The Environmental Management Team (EMT) of the SUD Project has carried 

out a process of selecting preliminary goals, targets and indicators for the selected 

areas of concern. The EMT consists of representatives for the core agencies 

dealing with aspects of Environmental Management for Kuching. The selected 

goals, targets and indicators have been reported in the SUD report “Preliminary 

Goals, Targets and Indicators for sustainable Urban Development in 

Kuching, Sarawak”(SUD-02-03/SUD-021-07). 

The preliminary indicators have constituted the starting point for elaborating 

the baseline study. 

A survey of existing and lacking data related to the selected indicators has been 

carried out to facilitate the elaboration of the baseline study. The results of the 

survey have been reported in the SUD report “Survey of Existing and Lacking 

Data on the SUD Project Indicators” (SUD-02-05). 


13


Based on this report, a data collection report was elaborated, specifying the 

compilation of extisting data and supplementary field studies in and elaboration 

of existing data (SUD report. River Quality Baseline Study. Data Collection 

(SUD-02-10)). 

A pilot study has been carried out for one of the Sg. Sarawak tributary Sg. Bintangor 

catchment area. The study aimed at gaining experience in getting and 

accessing relevant data from field studies and public files (SUD-02-09). 

2.2 River Quality Baseline Study 

The baseline study focuses on the selected preliminary indicators and the necessary 

background data (physical-, ecological- and social data etc.) to identify 

relations between sources and levels of deterioration of the environment. The 

indicators include: 

State indicators (water quality, quality of sediments, concentration of pollutants 

in aquatic organisms and ecosystem parameters); 

Load indicators (discharge from point and non-point sources); and 

Effort indicators (measures taken by the authorities to affect the constrains 

to the environment (e.g. inspection, enforcement) and the outcomes of the 

measures (performance)). 

The preliminary indicators are presented in Table 2.1. 

Table 2.1 Preliminary indicators for river quality (from “Preliminary goals, 

targets and indicators for sustainable urban development in Kuching, Sarawak 

(SUD report No SUD-02-03, SUD-02-07). 

Parameters 

State indicators Water quality pH, Dissolved oxygen, Biological oxygen 

demand (BOD), Chemical oxygen 

demand (COD), Total Suspended Solids 

(TSS), Ammoniacal nitrogen (NH4- 

N), Nitrates, Phosphorous, Oil and 

grease, Hg, Pb, As, Zn, Cd, Cr, Cu, Fe, 

Ni, Cyanide, Mn, Polyaromatic Hydrocarbons 

(PAH), Total Petroleum Hydrocarbon 

(TPH),Faecal and total coliforms 

Sediment pH, Ammoniacal nitrogen (NH4-N), 

Nitrates, Phosphorous, Oil and grease, 

Hg, Pb, As, Zn, Cd, Cr, Cu, Fe, Ni, 

Cyanide, Mn, Polyaromatic Hydrocarbons 

(PAH), Total Petroleum Hydrocarbon 

(TPH), Pesticides. 


14


Table 2.1 (continued) 

State indicators Pollutants in aquatic 

Parameters 

Concentration of contaminant XX and 

organisms 

YY in aquatic organisms (mussels) 

Ecological parameters 1) Diversity index 

2) Species of fish of yy family 

3) Species of invertebrates of zz family. 

Aesthetics 1) Level of smell by using standard 

method. 

2) Estimated weight of floatables collected 

from Sarawak River 

Load/effort indicators 

Households 1) Number of households 

with/without septic tanks or other 

treatment facilities treating sewage 

to standard X (Equivalent or better 

than standard B) 

2) Type of septic tanks or treatment 

facility (efficiency) 

3) The concentration of pH, TSS, 

Ammoniacal nitrogen, phosphorous, 

BOD,COD and E. Coli in 

treated effluent from households 

not exceeding xx based on laboratory 

analyses 

Agriculture 1) Total number of pig farms 

2) No of large pig farms with efficient 

waste treatment system 

3) Volume of discharge and SPP at 

large piggeries. The discharge of 

pH, TSS, Ammoniacal Nitrogen, 

Phosphorous, BOD and COD in 

discharge 

4) Yearly survey of agricultural plantations 

on the use of agrochemical 

xx 

5) Concentration of agrochemical xx 

in mainstreams draining plantations 

(upstream and downstream) 

6) Yearly inspection of extent of 

buffer zones around plantations 


15



Load/effort indicators 

Parameters 

Food outlets 1) Total number of food outlets 

2) Number of food outlets having 

efficient waste treatment facilities 

treating wastewater to level X 

(yearly inspection) 

3) Concentration of oil and grease and 

total suspended solids in wastewater 

based on laboratory analysis. 

Large Scale industries 

(LSI) and Small Medium 

Industries (SMI) 


1) Number of LSI and SMIs having 

efficient wastewater treatment system 

based on yearly inspection 

2) Concentration of xx and yy in 

treated effluent based on laboratory 

analysis 

River Vessels 1) Load of paint residue discharged to 

Sg. Sarawak by inspection of ship 

repair 

2) Concentration of organo-tin in 

mussels 

3) Number of oil spill incidents recorded 

The River Quality Baseline study is reported in three volumes: 

Volume 1: River Quality Baseline Study. Main Report. Existing River 

Quality, Pollution Sources and Environmental Management of Sg. Sarawak; 

Volume 2: River Quality Baseline Study. Mapping of Pollution Sources and 

Estimation of Pollution Load to Sg. Sarawak; and 

Volume 3: River Quality Baseline Study. Field Studies of Sediment Contamination 

and Benthic Invertebrate Fauna in Sg. Sarawak. 

Volume 1 of the river quality baseline study report is structured as follows: 

Section 3 briefly outlines the data collection; 

Section 4 provides general background information, which is relevant for 

the interpretation of the selected indicators for river quality. The section describes 

the physical background conditions (i.e. river catchment characteristics, 

climate, geology, hydrography and riverbed sediments). The river ecosystem 

in terms of vegetation, benthic invertebrate fauna and fish fauna is 

also described. Landuse in the catchment area for Sg. Sarawak and tributaries 

is described as well. The relevant institutions and the legal measures to 

administer the river quality are also briefly outlined; 

16


Section 5 describes the present river quality in terms of surface water quality, 

sediment quality, aesthetics and concentrations of pollutants in organisms 

as well as ecosystem impacts. The description is focused on the selected 

preliminary indicators for river quality; 

Section 6 outlines the sources of pollution and provides estimates of pollution 

loads from different sources in the sub-catchment areas for Sg. Sarawak, 

which are situated in Kuching City. Control and enforcement measures 

taken by the authorities to mitigate impacts on the environment are described 

as well. Other sources deteriorate river quality, including the effect 

of the downstream barrage of Kuching are also outlined. 

Section 7 is the discussion and conclusion section. The section provides: 

1. Characterisations of the degree of pollution of Sg. Sarawak; 

2. Identification of major sources of river pollution and the relative contribution 

to pollution of different sources; 

3. Assessment of the existing technical measures to reduce pollution load; 

4. Evaluation of the existing control and enforcement measures to manage 

river quality; and 

5. Assessment of the relevance of preliminary indicators and recommendations 

for indicators to be included in the EMS. 


17


3 Data Compilation 

The baseline study is based on the existing data provided by agencies and local 

authorities, and supplementary field and desk studies. 

3.1 Compilation of Existing Data 

Existing data were compiled and provided by the following aencies and Local 

Councils: 

National Resources and Environmental Board (NREB); 

Department of Irrigation and Drainage (DID); 

Department of environment (DOE); 

Kuching North City Hall (DBKU); 

Kuching City South Council (MBKS); 

Padawan Municipal Council (MPP); 

Land and Survey Department (L&S); 

State Health Department (SHD); 

Sarawak River Board (SRB); 

Department of Public Works (JKR); 

Kuching Barrage Management Sdn Bhd (KMB); 

Kuching Water Board (KWB); 

State Planning Unit (SPU); 

Ministry of Industrial Development (MID); and 

University of Malaysia Sarawak (UNIMAS). 


18


Details of the compilation are elaborated in the SUD report of “River Quality 

Baseline Study - Data Collection.” (SUD-02-10) A list of the compiled data is 

presented in section 8. 

3.2 Supplementary Field and Desk Studies 

During the initial preparation of the baseline study, the following types of data 

were identified as lacking and imperative for the baseline study: 

Point Source/Pollution load inventory; 

Biological/Ecosystem indicators; and 

Sediment data. 

The following field and desk studies were therefore conducted: 

Mapping and enumeration of different pollution sources, measurements of 

discharge of pollutants from households, food outlets (markets, restaurants 

etc.) and industries for the estimation of pollution loads from different 

sources; 

Field investigations of sediment contamination; and 

Field study of benthic fauna. 

Details on the methods applied for the estimation of pollution loads is presented 

in the Volume 2 of the River Quality Study. The methods applied for the sediment 

and benthos studies are outlined in the Volume 3. 

3.3 Assessment of Collected Data 

The compiled data and the supplementary field studies generally provide an 

adequate basis for the elaboration of the baseline study. However, additional 

data on enforcement measures and other effort indicators needs to be compiled 

to allow proper assessment. In addition, there are some data, which were identified 

as relevant but not collected due to various constraints such as: 

Technical constraints, which include: 

- Lack of standardising of data 

- Lack of standardised data registration forms 

- Technical procedures 

- Lack of computerising of files 

Institutional constraints, which include: 


19


- Classified data 

- Possessiveness to data 

- Competencies and capacities 

In the next phase of the SUD Project measures for overcoming some of these 

constraints will be prepared and specified, mainly standardising, registration 

forms, administrative procedures and computerising of files. 


20


4 Background Conditions 

4.1 River and Catchment areas 

Sg. Sarawak has two principal tributaries: Sg. Sarawak Kiri and Sg. Sarawak 

Kanan, rising in the mountain ranges to the south of Kuching at the border of 

Indonesia. The two tributaries meet near Batu Kitang, some 34 km upstream of 

Kuching. From Batu Kitang, the mainstream Sg. Sarawak meanders across a 

wide coastal flood plain and traverse Kuching. Downstream of Pending, the 

industrial area in the eastern part of Kuching, Sg. Sarawak confluence with Sg. 

Kuap and further downstream by Loba Batu Belat before discharging to the 

South China Sea at Muara Tebas (Fig. 4.1). 

In Kuching City, several small tributaries‟ discharges to Sg. Sarawak include 

Sg. Maong, Sg. Bintangor, Sg. Padungan Sg. Sekama, Sg. Bintawa and Sg. 

Biawak. Fig 4.2 shows the location of the tributaries in Kuching. 

A total of 21 drainage sub-catchment areas in Kuching are discharging to Sg. 

Sarawak on the stretch of the river from Sg. Maong to the Biawak causeway, 

east of Pending. The locations of these sub-catchment areas are indicated on 

Fig 4.3. 

The remaining part of the city, including the Sama Jaya Free Industrial Zone 

drains into Sg. Kuap, mainly via Sg. Tabuan. 

In 1997 a gated barrage was constructed through the Sejingkat Isthmus (Fig. 

4.2) and the river was blocked by causeways at Jalan Keruing and Jalan Bako 

in order to regulate the tidal influence on the river. 


21


Figure 4.1. Sg. Sarawak and its main tributaries. 


22


Figure 4.2. Tributaries of Sg. Sarawak in the Kuching City. 


23


Figure 4.3. Sub-catchment areas for tributaries and drains in Kuching discharging to Sg. Sarawak along the stretch from (and including) Sg. 

Maong to the causeway east of Pending. 


24


4.2 Physical Background Conditions 

4.2.1 Climate 

The climate in the catchment area of Sg. Sarawak is governed by the movement 

of the Inter-Tropical Convergence Zone and the associated movement of the 

warm air with the monsoons. 

The catchment area has high rainfall. The annual rainfall for Kuching varies 

between 3,000 and 5,000 mm. The wettest season is during the Northeast monsoon 

from November to March, with a peak rainfall in December to January 

typically higher than 400 mm per month. 

The minimum rainfall occurs in June and July. From April to July the mean 

monthly rainfall is in the range of 200 to 300 mm. The mean relative humidity 

is 85% with a maximum peak observed in December – March and a minimum 

peak occurring during the period of lowest rainfall in June – July. 

The temperature in the area ranges from about 22 0 C to 34 0 C. The warmest period 

is April to June and the lowest temperatures are encountered during the 

months from December to February (Meteorological Services Department 

Kuching, 2000). 

4.2.2 Geology 

The Sg. Sarawak river basin is geologically made up of rocks of Palaeozoic and 

Early Mesozoic ages (Annual Report Geological Survey of Malaysia, 1980). 

The oldest rocks are considered to be the pre-Upper Carboniferous schist and 

phyllite. Intrusive granite rocks are also common. The Sg. Sarawak delta deposition 

north of Kuching in a marine trough occurred throughout Jurassic giving 

rise to a sequence of predominantly argillaceous rocks with subordinate arenaceous 

rocks, chert, conglomerate and boulder slate and few lenses of conglomerate 

and limestone. 

Sedimentary rocks of Sg. Sarawak Kiri are mainly acid igneous and metamorphic. 

Limestone, shale and mudstone with thin beds of siltstone and fin-grained 

sandstone are common rock types of Sg. Sarawak Kanan (DID, 1988). 

The soils of Sg. Sarawak Kiri and Sg. Sarawak Kanan are mainly composed of 

recent alluvial and red yellow podzolic soils. Along the river valley, there are 

recent alluvial soils with generally shallow to deep, yellow to red loamy sands 

to clays on sedimentary, acid igneous and metamorphic rocks. To the north of 

the Sg. Sarawak Kanan catchment, patches of hard limestone can be found, 

while grey white podzolic soils are prominent in the south. 


25


4.2.3 Hydrography 

The upper reaches of Sg. Sarawak Kiri and Sg. Sarawak Kanan are narrow and 

shallow. They are situated in steep terrain with gradients in excess of 1 % and 

are therefore fast flowing. 

Downstream of the confluence of Sg. Sarawak Kiri and Sg. Sarawak Kanan 

below Batu Kitang and down to the sea, the river flows through a flat plain and 

is becoming gradually wider and the current speed decreases. 

Before the establishment of the barrage, the river was strongly influenced by 

the tide and intruding saltwater. The tidal influences propagated as far as Buso 

at Sg. Sarawak Kanan and Sebua at Sarawak Kiri, some 60 km from the estuary 

mouth. 

After the establishment of the barrage, the tidal influences and saltwater intrusions 

have been significantly reduced and a relatively stable water level has 

been established. The barrage has also reduced the river flow velocities. The 

reduced flushing effect of the tide and the reduced flow velocities have increased 

sedimentation of suspended matter. 

Today inflow of saltwater takes place when the barrage is opened for flushing 

every second weekday in contrast to the pre-barrage period when intrusion of 

saltwater took place twice a day. 

The barrage is opened for flushing in order to prevent oxygen depletion in impoundments 

in front of the barrage and to flush out organic matter accumulated 

in the sediment. 

4.2.4 Riverbed Sediments 

The sediments in the narrow, fast flowing upper reaches of Sg. Sarawak Kiri 

and Sg. Sarawak Kanan mainly consists of gravel (Table 4.1). 

Downstream of the confluence, where the current speed decreases, the riverbed 

sediments are mainly composed of fine-grained silt and clay (Table 4.1). 

The sand contents increase markedly in the Pending area, however, the sediments 

become silty again downstream of the barrage. The predominance of 

sand off Pending is probably an effect of the flushing procedure at the barrage. 

During flushing, the fine-grained particles of the sediment are suspended and 

transported downstream of the barrage where they resettle. This is supported by 

the fact that samples collected at Pending before the construction of the barrage 

had a silt content of 70%. After the construction of the barrage, the silt content 

in the Pending area decreased to 24% and the sand content increased to 76% 

(Table 4.1, Fig 4.4). 


26


Table 4.1 Grain Size Distribution of River Bed Sediments. 

Location Gravel 


(%) 

Sand 

(%) 

Silt (%) Clay (%) Refer- 

Upper reaches of Sg. Sarawak Kiri 96 4 0 0 1 

Upper reaches of Sg. Sarawak Kanan 97 3 0 0 1 

Sg. Sarawak main 

At Batu Kawa Bridge 2 20 63 15 1 

Upstream confluence Sg. Maong 0 24 68 8 2 

Downstream confluence Sg. Maong 0 30 64 23 2 

At Satok Bridge (pre-barrage) 5 95 0 0 1 

At Satok Bridge (post-barrage) 0 20 53 27 2 

Confluence Sg. Bintangor 0 4 59 37 2 

At Holiday Inn (pre-barrage) 2 98 0 0 1 

At Holiday Inn (post-barrage) 0 22 56 22 2 

Off Kuching Port Authority 0 25 49 26 2 

Downstream confluence Sg. Bintawa 0 52 37 11 2 

At Pending (pre-barrage) 0 19 70 11 1 

At Pending (post barrage) 0 76 24 0 2 

Downstream of Barrage 0 22 72 0 2 

Tributaries 

Sg. Maong (tributary of Sg. Sarawak) 0 20 56 24 1 

Ref 1: “Water Quality and Sediment Monitoring for Sg. Sarawak Flood Mitigation Options 

Study” as prepared by Chemsain Konsultant Sdn Bhd for Jurutera Jasa Sdn Bhd. 

Ref 2: SUD sediment study November 2000. Reported in Vol 3 of the River Baseline Study 

% 

80 

70 

60 

50 

40 

30 

20 

10 

0 

before barrage after barrage 

% sand % silt % clay 

Figure 4.4. Composition of sediments in Sg. Sarawak at Pending before and 

after the establishment of the barrage. Percentage of sand, silt and clay fractions. 

Hydrographic Section in Marine Department has carried out a survey on sedimentation 

for SRB. This study showed a slight increase of sedimentation rates 

after two years of operation of the barrage, due to the reduced river flow velocities. 

Samples collected at the Satok Bridge and at Holiday Inn before the estab- 

ence 

27


lishment of the Barrage, were much sandier compared to samples collected after 

(Table 4.1, Fig 4.5). This may reflect the increased sedimentation rate due to 

the barrage, but may of course also simply be due to the difference in sampling 

locations. 

% 

120 

100 

80 

60 

40 

20 

0 

Satok before Holiday inn before Satok after Holiday inn after 

Figure 4.5. Composition of sediments in Sg. Sarawak at Satok Bridge and 

Holiday inn before and after the establishment of the barrage. Percentage of 

sand silt and clay fractions. 

4.3 River Ecosystem 

%gravel % sand % silt % clay 

4.3.1 Riverbank Vegetation 

Sg. Sarawak Kiri and Sg. Sarawak Kanan flow through heavily vegetated primary 

and secondary rainforest in varying stages of succession that grows close 

to the waters edge. 

The vegetation changes below Batu Kitang, where the two tributaries meet. 

Wide beaches with reeds are encountered downstream of Batu Kitang. This is a 

result of the slowing down of the river flow rate. 

The vegetation along the river between Batu Kawa and the barrage is mainly 

mangrove- and nipah forest. Mangroves and nipah forests are encountered in 

tidal areas with fluctuating salinity. There is a concern that the decrease in salinity 

due to the barrage may impact the mangrove trees and nipah palms. 

4.3.2 Aquatic Vegetation 

Water hyacinth (Eichhornia crassipes) is abundant particularly at the confluence 

of feeder streams, channels and riverbank settlements where the concentration 

of nutrients is high. Explosive growth of water hyacinth is associated 

with increased discharge of nutrients in slow flowing waters. The establishment 

of the barrage resulting in slower water flow and reduced water exchange may 

cause rapid proliferation of water hyacinth especially in areas with high nutrient 


28


load. Reduction of the present sewage/nutrient discharge to the river will reduce 

the risk of water hyacinth growth. 

4.3.3 Benthic Invertebrates 

The SUD Project carried out a study of benthic invertebrates in Sg. Sarawak 

from upstream of Sg. Maong to downstream of the Barrage in November 2000. 

The study showed that oligochaete worms dominate the fauna in Sg. Sarawak 

upstream of the barrage. Tubificidae are the most common, with Tubifex occurring 

as the most common genus. Downstream of the barrage, oligochates were 

absent and marine molluscs dominate the fauna. The study is further discussed 

in section 5.5 in this volume and in the Volume 3 of the Baseline Study Report. 

A study carried out in 1995-1996 (KTA, 1997) indicated the presence of a large 

stock of the giant freshwater prawn (Macrobrachium rosenbergii) in the river 

from the Kuching area to the lower reaches of Sg. Sarawak Kiri and Sg. Sarawak 

Kanan. The giant freshwater prawn migrates downstream to spawn in 

brackish water. The installation of the barrage may have reduced the stock of 

the prawn in the river because the barrage acts as a barrier for the movement of 

sexually mature indivuduals to the brackish water downstream for spawning 

activities and the movement of juvenile stages upstream. However, the barrage 

does not completely block the migration of prawns as it is opened every second 

weekday. A interview with a fisherman in connection with the sediment and 

benthos studies carried out by the SUD Project in November 2000 indicated 

that Macrobrachium rosenbergii were often caught at the confluence of Sg. 

Bintangor and Sg. Sarawak. 

4.3.4 Fish 

A study of the composition of the fish fauna was undertaken prior to the establishment 

of the barrage. The study was carried out in the main river of Sg. Sarawak, 

Sg. Sarawak Kiri and Sg. Sarawak Kanan during the period from May 

1995 to February 1996 (KTA, 1997). 

Table 4.2 and 4.3 show the fish families and species encountered in the three 

sections of the river system. It is evident that the composition of the fish fauna 

in the main river Sg. Sarawak is very different from the fauna in the upstream 

tributaries, Sg. Sarawak Kiri and Sg. Sarawak Kanan. Fish fauna composition 

changes gradually along the river due to changes in environmental conditions. 

The most important being: depth and width of stream/river, current velocity, 

riverbed substrate, turbidity, availability of preferred food and influence of 

tide/salinity. 

The upper reaches of Sg. Sarawak Kiri and Sg. Sarawak Kanan are narrow, 

shallow, fast flowing and clear streams, which flow over gravel and rocky bottoms. 

Here species from the Balitoridae and Sisoridae families are dominant. 

Fish from the Bagridae family are also common. Further downstream, species 

from the Cyprinidae family gradually become dominant and at the confluence 

of Sg. Sarawak Kiri and Sg. Sarawak Kanan, the fish Mystus sp. replaces the 

Cyprinids. 


29


Downstream of the confluence, the river flows through a flat plain and is becoming 

gradually wider. The current speed decreases, the waters are turbid and 

the riverbed is silty. All these environmental changes affect the composition of 

the fish fauna. In 1995-1996, this part of the river was tidally influenced with 

intrusion of saltwater/brackish water twice a day. The fish fauna comprised 

both freshwater and marine species. About 66% of the total numbers of species 

caught were marine or brackish and the remaining 34% were freshwater species. 

After the establishment of the barrage in 1997, the inflow of saltwater has 

been reduced. Today, the inflow of saltwater takes place when the barrage is 

opened for flushing every second weekday compared to the pre-barrage period 

when intrusion of saltwater took place twice a day. The stocks of marine and 

brackish water species in the lower reaches of Sg. Sarawak will therefore, 

probably decrease due to the presence of the barrage. 

Table 4.2 Number of species of different fish families caught in Sg. Sarawak, 

Sg. Sarawak Kiri & Sg. Sarawak Kanan during the period May 1995- 

February 1996. 

Family Number of species 

Sg. Sarawak Kiri 

Number of species 

Sg. Sarawak Kanan 


Number of species Sg. 

Sarawak Proper 

Antennariidae 1 

Anguillidae* 1 

Ariidae* 3 

Bagridae 3 3 2 

Balitoridae 3 1 

Carangidae* 1 

Channidae 2 1 

Clariidae 1 

Cyprinidae 11 4 1 

Dasyathidae 1 

Eleotrididae* 3 

Gobiidae* 2 

Hemiraphidae 1 1 

Lutjanidae* 1 

Mastacembelidae 1 1 1 

Mugilidae* 1 

Ophicephalidae 1 

Plotosidae 1 

Polynemidae 1 

Scianenida 3 

Siluridae 1 

Siganidae 1 

Sisoridae 3 1 

Tetradontidae 1 1 1 

Toxotidae 1 1 1 

*Anguillidae, Ariidae, Carangidae, Eleotridae, Gobiidae, Dermogenys sp. Mugilidae and Lutjanidae 

are primarily marine or brackish water fish families that may swim upstream into fresh water (Ref. 2). 

30


Table 4.3 List of species of fish caught in Sg. Sarawak, Sg. Sarawak Kiri and 

Sg. Sarawak Kanan during the period May 1995-February 1996. 

Family Species Sg. Sarawak 

Kiri 


Sg. Sarawak 

Kanan 

Sg. Sarawak 

Main 

Antennariidae Antennarius sp X 

Anguillidae* Anguilla sp. X 

Ariidae* Arius bilineatus X 

Arius maculatus X 

Arius venosus X 

Bagridae Leiocassius micropogon X X 

Mystus sp. 1 X X X 

Mystus sp. 2 X X X 

Balitoridae Gastromyzon danumensis X X 

Homaloptera nebulosa X 

Nemachilus kapuaensis X 

Carangidae* Caranx sp X 

Channidae Chana lucius X X 

Cyclocheiltichtys apogon X 

Clariidae Clarias sp X 

Cyprinidae Paracrossochiluys vittatus X X 

Puntius binonatus X 

Puntius brevis X 

Punthius lateristriga X X 

Punthius sealei X 

Rasbora borneensis X X 

Rasbora caudimaculata X 

Rasbora sarawakensis X 

Rasbora spilotaenia X 

Rasbora sp. X X 

Tor sp X X 

Dasyathidae Himantura signifer X 

Eleotrididae* Bunaka gyrinoides X 

Oxyeleotris marmorata X 

Eleotris sp. X 

Gobiidae* Glossogobius sp X 

Periohthalmus sp X 

Hemiraphidae Dermogenys sp* X 

Hemiraphodon sp X 

Lutjanidae* Lutjanus johnii X 

Mastacembelidae Mastacembelus sp. X X X 

Mugilidae* Liza sp X 

Ophicephalidae Ophicephalus sp X 

Plotosidae Plotosus sp X 

Polynemidae Eleutheronema tetradactylum X 

Scianenida Boesemania microlepis X 

Pana microdon X 

Johnius coitor X 

31



Family Species Sg. Sarawak 

Kiri 


Sg. Sarawak 

Kanan 

Sg. Sarawak 

Main 

Siluridae Kryptoterus lais X 

Siganidae Siganus vermiculatus X 

Sisoridae Glyptothorax plathypogon X X 

Glyptothorax platypogonoides 

X 

Glyptothorax major X 

Tetradontidae Xenopterus sp X X X 

Toxotidae Toxotes sp X X X 

*Anguillidae, Ariidae, Carangidae, Eleotridae, Gobiidae, Dermogenys sp. Mugilidae and Lutjanidae 

are primarily marine or brackish water fish families that may swim upstream into fresh water (Ref. 2). 

4.4 Landuse 

Kuching is the principal urban center at the Sg. Sarawak River system. There 

are numerous smaller towns and villages in the river valleys upstream of 

Kuching including Batu Kawa, Batu Kitang, Siniawan and Bau. River valleys 

have been developed for agriculture and the river is used for transportation, 

fishing and water extraction. 

4.4.1 Urban Landuse 

Kuching 

Kuching is a quite large city with a population of about 450,000 according to 

the recent population census. 

Historically, the built-up area of the city was concentrated on the south bank of 

the river. Apart from the village settlements along the river, the north bank was 

largely undeveloped until the early 1970s when the major bridge crossing at 

Satok and the new State legislative and administrative hub were constructed. 

The development of the major government establishments therefore created the 

growth impetus for the development „across river‟ called Petra Jaya, which had 

continued to gain momentum with the road connection to the resort areas at 

Santubong and Damai. 

The landuse pattern of Kuching has been analysed in connection to the SUD 

Project and comprised the landuse of the catchment areas discharging to Sg. 

Sarawak. 

The City‟s industrial zone is concentrated to the eastern sector at Pending (fig. 

4.6). In addition, there is an industrial area southeast of the study area near Sg. 

Kuap, the Sama Jaya Free Industrial Zone. There is also a smaller industry zone 

at Demak Laut. 

32


The Central Business Centre is located in the middle of the City where there are 

also residential and institutions areas. Predominantly residential areas are located 

to the south and west (Fig 4.6). 

Industrial development has haphazardly proliferated into the Batu Kawa and 

Batu Kitang areas in recent years, due to the lack of such sites in the existing 

industrial zones and of their proximity to population areas. The establishments 

include garage workshops, cement batching plants, warehouses, etc. 

A number of major commercial centres are spread over the south bank. They 

include the Sekama and the Kenyalang Park shopping centres in the eastern 

sector and the Satok/Rubber Road, the Green Road and the Central 

Park/Timberland commercial centres in the western sector. A major commercial 

centre is also currently being constructed at Batu Kawa. 

At the north bank, government establishment forms the core of the development, 

and a new town centre named Medan Raya is currently being built in that 

vicinity. There are also a number of institutional buildings located in the area, 

including a private hospital, the State mosque and library. Residential development 

is also rapidly being undertaken in Petra Jaya. 

The landuse in Kuching is described in detail in terms of pollution sources in 

Volume 2 of the River Baseline Study and in section 6 of this report. 

Batu Kawa 

Batu Kawa is a small bazaar, with only two rows of shophouses situated on the 

left bank of Sg. Sarawak. 

Batu Kitang 

Batu Kitang is a small service centre, situated at the Jalan Batu Kitang/Sg. Sarawak 

Kiri Bridge crossing near the Kuching Water Board water treatment 

plant. 

Siniawan 

Siniawan is a small bazaar situated on the south bank of Sg. Sarawak Kanan 

approximately mid-way between Kuching and Bau. 

Bau 

Bau is an urban centre situated some 30 km from Kuching along Sg. Sarawak 

Kanan. It is the administrative centre of Bau district. The town was founded on 

gold and antimony mining, an activity which has gradually declined. 


33


Figure 4.6. Landuse of catchment areas in Kuching discharging to Sg. Sarawak 


34


4.4.2 Agriculture 

Around 70% of the catchment areas of the Sg. Sarawak system are used for agriculture. 

The most significant farming activities are shifting cultivation, horticulture 

mixed farming and pig rearing. The importance of oil palm farming is 

increasing. 

Shifting cultivation 

Shifting cultivation covers by far the largest area within the catchment area (i.e. 

47%). Shifting cultivation in Sarawak is a hill-padi based cropping system, 

which is practised by the indigenous people. Shifting cultivation is a slash-andburn 

cultivation system in which the use of the fields is rotated. There has been 

a general decline in the cultivated area over the last decade due to the gradual 

switch to cash crops. 

Horticulture and mixed farming 

Around 10% of the catchment area are utilised for horticulture and mixed farming. 

This settled form of agriculture involves a wide range of crops such as 

vegetables, fruits, cocoa, rubber and pepper (Table 4.4). These crops are cultivated 

on a small holder basis on scattered individual farms. Most of the fruits 

and vegetables are sold on the markets in Kuching City. 

Table 4.4 Main vegetables and fruits grown in the catchment area. 

Vegetables Leafy vegetables: Chai Sim, Kai Lan, Kang Kong, Bayam, Pak 

Choi, Changkor Manis etc 

Tubers: yam, sweet potato, Lobak, groundnuts 

Fruity vegetables: Cucumber, long bean, french bean, ladies 

fingers, chilli, angle luffa, bitter gourd, pumkin, white gourd, 

winged bean 

Fruit Durian, rambutan, mango, mangosteen, langsat, guava coconuts. 

papaya, banana, guava, citrus and starfruit 

Pig rearing 

There are several large commercial pig farms in the catchment area. They are 

located in the Batu Kawa, Batu Kitang, Semaba/Kung Phin, Siniawan/Tg. 

Durian and Buso areas (Fig. 4.7). The farm size ranges from farms with 100 

heads to sizeable commercial farms of 3500 heads (Table 4.5). 

Table 4.5 Number and size of large commercial pig farms in the catchment 

area. 

Number of pigs Number of farms 

100-500 8 

500-1000 8 

1000-2000 8 

2000-3500 3 


35


Oil palm 

Oil palm plantation has recently been introduced into the study area. The oil 

palms are grown on estates of 100 –1,000 ha. Significant development of oil 

palm estates is expected to take place in the future. 


36


Figure 4.7. Location of pig farms in the catchment areas of the Sg. Sarawak 

system. 


37


4.4.3 Fishery and Aquaculture 

A study of the fishery in the river was carried out in 1995-1996 prior to the establishment 

of the barrage. 

The lower sections of the river from the confluence of Sg. Sarawak Kiri and Sg. 

Sarawak Kanan to the Pending area in Kuching was an important fishing 

ground supporting a commercial fishery of some significance. In 1995-96, there 

were some 15 full time fishermen and 30 part time fishermen. In addition, a 

considerable leisure fishery was taking place especially in the weekends by up 

to 100 people. 

Although fishing takes place in Sg. Sarawak Kiri and Sg. Sarawak Kanan they 

are not important fishing grounds and they do not support any commercial fishing 

activities. 

The fishery in the mainstream Sg. Sarawak was carried out by the use of gill 

nets, hook and lines, long trap nets (belat), cast nets and scoop net. 

Gill nets were mainly used from downstream of Holiday Inn to Pending Port. 

Long trap nets (belat) were used upstream of Satok Bridge and cast nets and 

hook lines were used throughout the whole stretch of the river. 

The total annual revenue generated from Sg. Sarawak fishery between Pending 

Port and the confluence Sg. Sarawak Kiri and Sg. Sarawak Kanan was estimated 

at RM 275,000. The most common species caught were freshwater giant 

prawns (Macrobrachium rosenbergii) and the fish species Mystus spp. and 

Oxyeleotris marmorata. 

Brackish fish species made up about 75 % of the number of fish species caught 

in 1995-96. With the construction of the barrage, the number of brackish species 

above the barrage is expected to decline significantly. So is the stock of 

giant freshwater prawn, which spawns in brackish water (Cf. sections 4.3.2 and 

4.3.3). It is not known to what extent the barrage has affected the fishery today, 

but it will probably not be possible to sustain the 1995-96 level of fishing. A 

fisherman interviewed in November 2000 indicated that freshwater giant 

prawns are still often caught at the confluence of Sg. Bintangor and Sg. Sarawak, 

but only a thorough fishery investigation can elucidate the effects of the 

barrage on the fishery. 

There are no aquaculture activities in the Sg. Sarawak Proper. However, pond 

culture is very common among farmers in the catchment area. In 1996, it was 

estimated about 1,900 fishponds were operated by 1,200 farmers (Ref. 1). The 

ponds were mainly located along the Bau Kawa/Bau-Lundu road, the Musi area 

and in Bau. Most of the ponds are rainfed with no connection to the river. 


38


4.4.4 Mining 

There are gold, silver, mercury, antimony and kaolinitic clay deposits in the Sg. 

Sarawak catchment area. Occurrences of copper, lead, zinc and iron have also 

been noted but are not of great significance. 

Most of the known mineral deposits are located in the Bau district. Since the 

beginning of the last century gold and silver has been mined here. Previously 

mercury and antimony was exploited as well. No mining activities take place 

today. 

4.4.5 Water Extraction 

Approximately 95% of the water supplies for Kuching City are obtained from 

Sg. Sarawak Kiri via Kuching Water Boards pumping station at Batu Kitang. 

The river basin of Sg. Sarawak Kiri above this point has been gazetted as a water 

catchment area to protect this important water resource. 

4.5 River Quality Management in Kuching 

Several agencies undertake and/or have a mandate to undertake separate functions 

relevant to river water quality management. Below follow a brief description 

of the functions and related agencies. In Appendix 2, there is an overview 

of the State administration, which is organised in a Chief Minister‟s Department, 

10 ministries and local authorities. In Appendix 3, there is a brief summary 

of relevant activities and mandates. 

4.5.1 Goals Setting 

With the recent amendment to the Natural Resources and Environment Ordinance 

(NREO) in May 2001, the overall State‟s environmental management has 

explicitly been delegated to the Natural Resources and Environment Board 

(NREB). According to section 5m, the Board may set environmental quality 

goals and determine and take the necessary measures for achieving such goals. 

According to section 5c, this power includes issuing of directions or orders to 

other environmental authorities. 

The present baseline study is conducted as a precondition for determining the 

future goals for river water quality. According to section 5n the NREB can direct 

any environmental authority to undertake monitoring and reporting of environmental 

quality. This power is required for procuring the comprehensive 

baseline studies as well as for the continuous updating of the data for the periodical 

environmental statements. 

On a federal level the Environment Quality Act (EQA) delegates a broad mandate 

to the Department of Environment (DOE) to recommend on environmental 

policies to the Minister and to conduct environmental planning (section 3c&o). 

According to section 51(ee), the Minister can issue regulations on ambient water 

quality standards. Until now, no regulation has been issued but a set of “In- 


39


terim National Water Quality Standards” (INWQS) has been prepared. State 

goals will as, a minimum, have to conform to federal standards. 

Other State‟s ordinances also include the aspect of river quality management. 

According to the Water Ordinance (WO), issues on conservation, protection, 

development and management of the water resources of the State are among the 

duties and functions of the Water Resources Council. 

Landuse related to riverbanks is regulated by Land and Survey Department 

(L&S). Development of land is regulated by State Planning Authority (SPA). 

Sarawak Rivers Board (SRB) has specific powers to regulate activities along 

the banks of gazetted river (SRC 16 & 22). 

4.5.2 Water Quality Monitoring and Reporting 

It is the duty of DOE to produce a yearly report on the state of the environment 

in Malaysia (EQA, section 3). This yearly report includes the status of the water 

quality in the major Malaysian rivers. The information presented is based on 

an overall index, calculated from 7 main water quality parameters. 

NREB undertakes river monitoring of certain water quality parameters in the 

main rivers. 

Other State agencies carry out monitoring for specific purposes. There are no 

explicit legal provisions regarding this monitoring. Monitorings are carried out 

by SRB for river water quality, Public Works Department (JKR) and Kuching 

Water Board (KWB) for drinking water quality. Drainage and Irrigation Department 

(DID), JKR and Kuching Barrage Management carry out hydraulic 

measurements to monitor flooding, drainage etc. 

4.5.3 Regulatory Measures 

A substantial number of agencies are involved in regulation of the discharge of 

wastewater, sewage and solid waste to the river. 

Standards for discharge to inland waters are generally issued by DOE according 

to EQA section 21 and 51(ee). The present standards are issued as the 1979 

Environmental Quality Sewage regulations. NREB can similarly regulate discharge 

according to NREO 18(u&v). 

Hazardous (scheduled) waste is separately regulated by the EQA. 

Prior approval of activities, which may cause discharge to inland waters, is 

conducted by several agencies. 

Approval of EIAs for specific activities is conducted by DOE and NREB respectively. 

The division of tasks is specified in the regulations. DOE generally 

deals with industrial and infrastructural projects while NREB deals with landuse 

projects. 


40


Licensing of specific activities is conducted by: 

DOE (Crude palm oil, raw natural rubber and activities discharging higher 

concentrations of polluting substances than determined in the Environmental 

Quality Sewage regulations); 

Public Health Authorities and Local Authorities (markets, food outlets, 

preparation and processing of food, hotels, petroleum storage); 

Veterinary Health Authorities (abattoirs, meat processing, rearing of livestock); 

Ministry of Agriculture (aquaculture); and 

Land and Survey Department (mining, certain activities within prescribed 

urban areas). 

Permission from Sarawak Rivers Board (SRB) is required for discharge of effluents 

or sewage into navigable (gazetted) rivers or into drains that discharge 

into gazetted rivers (Sarawak Rivers Cleanliness bylaw (SRC) section 13). 

Discharge of pollutants into inland waters is prohibited according to EQ Sewage 

Regulation (Section 6), NREO (section 30a), the Local Authorities Ordinance 

(section 117), Local Authorities (Cleanliness) By-law (section 18) and 

Sarawak Rivers Ordinance (gazetted rivers) (Section 33). Specific prohibitions 

are issued according to the Water Ordinance (WO) for designated water catchment 

areas. 

Orders or directives relating to discharge into inland waters may be issued by 

DOE (EQA section 31), NREB (NREO 10(j)), Local Authorities (LAO section 

112 (nuisances)) and SRB (SRC section 22 (gazetted rivers)). 

4.5.4 Wastewater and Sewage Systems 

In general, the local authorities have an obligation to keep the area under their 

jurisdiction clean and hygienic in accordance with the Local Authority Ordinance 

(section 91). Section 104 and 105 give mandates to establish, maintain 

and carry out sanitary services including removal or otherwise dealing with 

night-soil and all kinds of effluent, and to issue relevant rules and by-laws. 

Today, the public stormwater drains serve as the main sewage system. Construction 

and maintenance of public drains and sewage systems are included in 

the powers delegated to the Local Authorities (LAO 132 & 138). The works are 

typically carried out by JKR on behalf of the Local Councils. DID have been 

increasingly involved in planning and implementing the major drainage systems 

(trunk systems) because of the accelerated urbanisation of the State. The 

involvement is not based on specific legal provisions. Drainage integrated in 

development projects for new areas are conducted by the developer and handed 

over to the Local Councils at project completion. However, the Local Councils 

have no obligation to accept such hand over. 

Construction and operation of sewage treatment (sewage farms and sewage 

disposals works) are similarly delegated to the local authorities (LAO 134). 


41


However, State major development projects typically derive from the State 

Planning Unit (SPU) as special projects. Future centralised sewage treatment 

for Kuching is in accordance with this expected to be initiated by SPU. 

Every Government agencies and Local Authorities shall submit projects for the 

protection and the environment to the NREB for its recommendation before 

submitting to the State Parliament for approval (NREO 9). 

Establishment of sewers or drains carrying sewage or effluents to be discharged 

into a gazetted river requires a permission from SRB (SRC 9). In addition, SRB 

has specific powers to order dismantling, demolishing or alteration of the position 

of drains and sewers to avoid discharge of effluents and sewage into gazetted 

rivers (SRC 8 & 10). Similarly SRB has specific powers to require the 

treatment of the effluents (SRC 10). 


42


5 River Quality 

Sg. Sarawak and its tributaries in Kuching are receiving sewage and wastewater 

from a wide variety of sources in Kuching including households, food outlets 

(markets, restaurants etc.) and industries. In addition, Sg. Sarawak receives pollutants 

from agriculture, mining and landclearing activities as well as sewage 

from cities and villages upstream of Kuching. The sources of pollution and pollution 

loads from different sources are described in section 6. 

5.1 Potential Impacts of the Discharge of Wastewater 

Sewage and wastewater deteriorate the water quality of the tributaries and the 

main river, the extent of deterioration depending on the amount of sewage and 

the water exchange. 

The potential impacts from sewage discharge can be grouped into: 

Impacts of organic matter and nutrients; 

Impacts due to pathogenic microorganisms; and 

Impacts of toxic substances. 

Organic matter 

The impacts of the discharge of organic matter in sewage are basically caused 

by the microbial degradation of organic compounds. In a river, some significant 

effects are: 

After discharge, microorganisms (bacteria, fungi and ciliates) on the riverbed 

and other surfaces degrade the organic matter in the sewage, consuming 

oxygen during the process; 

The Biological Oxygen Demand (BOD), which is a measure of the biodegradable 

organic matter in the water, increases dramatically at the outlet, 

but succeedingly the BOD decreases due to sedimentation of particulate 

matter and to degradation of dissolved organic matter (Fig 5.1 A); 

The oxygen consumption of the sediment increases immediately downstream 

of the outlet due to the microbiological activity and the concentra- 


43


tion of oxygen in the sediment and water decrease. However, the oxygen 

consumption of the sediment decrease further downstream concurrently 

with the decrease of organic matter and the concentration of oxygen increases 

again (Fig 5.1A); 

The degradation of organic matter result in the release of ammonium 

(NH4 + ) and phosphate (PO4 3- ). The ammonium is nitrified by microorganisms 

to NO3 - consuming oxygen in the process (Fig 5.1 B); 

These processes affect the invertebrate fauna in the river due to changes in 

the supply of food, structure of sediment and concentration of oxygen. Low 

oxygen levels and high organic content of the sediment favours organisms 

which can tolerate low oxygen concentrations and which are deposit feeders 

subsiding on organic detritus and its associated microflora. When dissolved 

oxygen reaches very low level, the organisms die. 

The degradation of organic matter may also cause offensive odours. In 

oxygen depleted environments, extremely malodorous compounds like 

methane and hydrogensulphide is thus released. 

Pathogenic organisms 

Sewage may contain pathogens (disease-causing organisms) such as hepatitis 

B, cholera, and typhoid. Faecal coliforms, which are bacteria found in the intestinal 

tracts of mammals, including humans, are measured as an indicator of the 

extent of contamination by pathogens. Most faecal coliforms are not hazardous 

to humans; however, they provide an indication of the amount of faecal matter 

present, which may be contaminated with other pathogens. 

Toxic substances 

Hundreds of potentially toxic substances are found in sewage effluent. These 

include metals (such as mercury, arsenic, lead, chromium, copper, cadmium, 

and silver), hydrocarbons, synthetic organic chemicals, and chlorine. 

The contaminants are continuously accumulated in the sediments of the river. 

They are generally adhered to fine-grained particles in the sewage and settled 

with sediments on the riverbed. Some of these contaminants can remain in the 

environment for a long time and many of them cannot be degraded (such as 

heavy metals). 

Some metals and organic compounds may accumulate in organisms and are 

passed up the food chain to predator species. This process, known as biomagnification 

or bioaccumulation, is one of the ways that contaminants in sewage 

effluent may affect people. 


44


Figure 5.1. The effects on the discharge of sewage in a river in terms of concentrations 

of oxygen, BOD, NH4 + and NO3 - in the water column with increasing 

distance from the outlet. 


45


5.2 Surface Water Quality 

The assessment of the surface water quality of Sg. Sarawak focuses on parameters, 

which have been chosen as preliminary indicators for water quality in the 

EMS for Kuching i.e.: 

pH, DO, BOD, COD, Total Suspended Solids, Oil & Grease; 

Nutrients (Ammoniacal Nitrogen, Nitrate, Total Nitrogen, Phosphorus); 

Heavy Metals (Hg, Pb, As, Zn, Cd, Cr, Cu, Fe, Ni, CN, Mn); and 

Coliform Counts. 

Evaluation of the present water quality is based on water quality data collected 

by NREB, KWB and UNIMAS in year 1999 and 2000. Descriptions of changes 

in water quality since 1984 are based on data from DOE. 

For the assessment of the present water quality the selected monitoring locations 

are grouped in various zones as follows (Cf. Table 5.1): 

Zone A, comprising sampling sites on Sg. Sarawak Kanan; 

Zone B, comprising sampling sites on Sg. Sarawak Kiri; 

Zone C, comprising sampling sites on Sg. Sarawak Proper from Batu Kawa 

to upstream of Satok Bridge; 

Zone D, comprising sampling sites on Sg. Sarawak Proper from Sg. Satok 

Bridge to downstream of Barrage; 

Zone E, comprising sampling sites on comprising sampling sites on Sg. 

Maong (Tributary discharging to Sg. Sarawak); 

Zone F, comprising sampling sites on Sg. Bintangor (Tributary discharging 

to Sg. Sarawak); 

Zone G, comprising sampling sites on Sg. Padungan (Tributary discharging 

to Sg. Sarawak); 

Zone H, comprising sampling sites on Sg. Sekama (Tributary discharging to 

Sg. Sarawak); and 

Zone I, comprising sampling sites on Sg. Tabuan (Tributary discharging to 

Sg. Kuap). 


46


Table 5.1 provides an overview of assessment zones and data sources and Figure 

5.2 indicates the location of monitoring sites in the City of Kuching. 


47


Table 5.1 Overview of data and monitoring sites used in the assessment of the 

present water quality. Numbers in parentheses refer to station numbers. The 

locations of these stations are presented in Fig. 5.2. 

Selected Monitoring Location Sources 

SMK Bau 

Wind Cave 

Zone A 

Bau Water Intake Point 

Zone B 

Kpg. Bukit Panchor 

Batu Kitang Intake Point 

Zone C 

Kampung Batu Kawa 

Batu Kawa Bridge 

Zone D 

Under Satok Bridge (W2) 

Near Holiday Inn Discharge 

Point (W3) 

Bako Causeway (W9) 

Upstream Barrage (W7) 

Downstream of Barrage (W8) 

 

Zone E 

Sg. Maong (N1) 




Zone F 

Sg. Bintangor (W2) 

Zone G 

Sg. Padungan (W4) 

Zone H 

Sg. Sekama (W5) 

Zone I 

Sg. Tabuan (St 1-St 6) 


(a) NREB‟s River Watch Monitoring Programme: Water 

Quality Data for Southern Region 

May – December 1999 

January – August 2000 

(b) Kuching Water Board: Raw Water Quality Report for 

the year 1999 and 2000 (up to Oct.) 

(c) NREB‟s River Watch Monitoring Programme: Water 


January – December 1999 


(d) Kuching Water Board: Raw Water Quality Report for 

the year 1998, 1999 and 2000 (up to Oct.) 

(e) Kuching Water Board Raw Water Quality Reports for 

the years 1998, 1999 and 2000. 

(f) NREB‟s River Watch Monitoring Programme: Water 


January – November 1999 

January – August 2000 

(g) NREB‟s River Watch Monitoring Programme: Water 


January – November 1999 


h) NREB‟s River Watch Monitoring Programme: Water 

Quality Data for Southern Region. January – September 

2000 

i) NREB‟s River Watch Monitoring Programme: Water 

Quality Data for Southern Region. January – September 

2000 

j) NREB‟s River Watch Monitoring Programme: Water 


January – September 2000 

k) UNIMAS study. Sampling in September and December 

1999 

48


Figure 5.2. Water Quality Monitoring Sites in the City of Kuching. 


49


5.2.1 General Overview 

The water quality data from NREBs‟ River watch programme for year 2000 is 

used to compare the degree of pollution of different stretches of Sg. Sarawak 

and tributaries. For this year, there are simultaneous monthly measurements 

from Sg. Sarawak Kiri, Sg. Sarawak Kanan, Sg. Sarawak Proper, Sg. Maong, 

Sg. Bintangor, Sg. Padungan and Sg. Sekama, which are not available from 

previous years. 

Organic matter, nutrients and oxygen 

The concentrations of BOD and ammoniacal nitrogen are low in Sg. Sarawak 

Kiri and Kanan. Correspondingly, the oxygen conditions are good with mean 

concentrations of oxygen of more than 5 mg/l (Figure 5.3). 

The concentrations of BOD and ammoniacal nitrogen are also low in the part of 

Sg. Sarawak, which is facing Kuching. However, the concentration of oxygen 

is significantly decreased compared to the zones upstream of Kuching. The 

mean concentration is around 4 mg/l. Oxygen concentrations, which are below 

4 mg/l may cause harmful effects on sensitive organisms in the river. The low 

BOD values along this stretch of the river may not be literally taken as an indication 

of low organic loading in the river water. In a warm tropical climate 

where biodegradation of organic material is rapid, low dissolved oxygen concentrations 

as those observed in the lower reaches of Sg. Sarawak are most 

likely due to decomposition of the high loading of organic matter. 

The tributaries situated in Kuching are extremely polluted with very high concentrations 

of BOD and ammoniacal nitrogen with very poor oxygen conditions. 

In fact, concentrations below 2mg/l are consistently encountered. Very 

few organisms can survive in such low concentrations of oxygen. 

The poor water quality in the tributaries and Sg. Sarawak in Kuching is mainly 

due to the discharge of untreated sewage from the drains in the city. 


50


DO;BOD mg/l 

10 

9 

8 

7 

6 

5 

4 

3 

2 

1 

0 

Kiri Kana Sg Sarawak Sg Maong Sg Bintangor Sg Padungan Sg Sekama 

DO BOD NH4 

Figure 5.3. Mean concentration of Dissolved oxygen, BOD and ammoniacal 

nitrogen (NH4-N) in 2000 in different zones of the Sg. Sarawak as defined 

above. (Sg. Sarawak corresponds to Zone D: i.e.to the main stretch of Sg. Sarawak 

Proper from Sg. Satok Bridge to downstream of Barrage. 

Odours 

The SUD Project has introduced an internationally recognised standard method 

for the assessment of the intensity of smell in river and drain water in Kuching. 

The method determines Threshold Odour Number (TON) by a panel of smellers. 

The TON is defined as the number of dilutions of a water sample which is 

necessary in order to obtain a mixture in which odour is just perceived with certainty 

by the panellists, i.e. the higher the threshold odour number the higher 

intensity of smell. The method is described in SUD document SUD-02-29 “Determination 

of odour characterisation in water”. 

Table 5.2 presents the results obtained during the introduction of the method. It 

is evident that there is no or very little odour in Sg. Sarawak Proper. In contrast, 

the waters in the tributaries Sg. Bintangor and Sg. Sekama are very smelly and 

the drain water from the market at Petanak smell extremely strong. 


4 

3,5 

3 

2,5 

2 

1,5 

1 

0,5 

0 

NH4 mg/l 

51


Table 5.2 Results of testing of odours in river water. April and May 

2001.Threshold odour number determined by a panel of smellers. For the 

results indicated as 16000 > 16000 

Zone F (Sg. Bintangor) > 16000 > 16000 

Zone G (Sg. Padungan) > 16000 > 16000 

Zone H (Sg. Sekama) > 16000 > 16000 

Heavy metals and other hazardous pollutants 

The levels of heavy metals in water are generally very low and below the detection 

limits, except for iron and manganese (Cf. Appendix 1). The levels of iron 

and manganese is generally violated the Malaysian water quality standards (Cf. 

below) at all monitoring stations in the Sg. Sarawak system. 

The high iron and manganese concentrations are due to natural processes and 

not primarily a result of human activities, although the discharge of wastewater 

may contribute to increased levels. Results from 1999 indicate that the concentrations 

of iron in Sg. Sarawak Kiri are at the same level as those encountered 

52


in the heavily polluted Sg. Maong and higher than the levels in Sg. Sarawak 

main fronting Kuching (Zone D) (Table 5.4). 

High background concentrations in surface water are common in tropical natural 

waters as iron is constantly leached from the iron-rich soil and rocky substrates 

(Menon & Murtedza, 1999). Leaching of iron is particularly significant 

in swampy areas such as peat and freshwater swamps, nipah forests and mangroves, 

which are abundant in the Sg. Sarawak catchment area. The soils in 

such areas are waterlogged and anaerobic. In the anaerobic, waterlogged soil, 

the solubility of iron increases. Insoluble Fe +++ is reduced to soluble Fe ++ , 

which is then transported via groundwater to the river. The solubility of manganese 

increases in anaerobic swampy area in the same way as iron (Chapman, 

1997). 

The available data indicate that agrochemicals and pesticides are generally below 

detection limits (Menon & Murtedza, 1999). 

Table 5.4 Mean concentrations of iron in different zones of the river in the 

year 1999. Wet season: Nov-Feb. Dry season: Mar-Oct. Data not available 

for year 2000 and for Zone A and Zones F-H 

Zone Mean concentration 

wet season (mg/l) 


Mean concentration 

dry season (mg/l) 

Zone B Sg. Sarawak Kiri 2.3 1.0 

Zone C (Batu Kawa to Satok bridge) 0.7 0.8 

Zone D (Satok to Barrage) 0.9 0.8 

Zone E (Sg. Maong) 2.0 1.3 

5.2.2 Water Quality Classification of Different Zones 

The data have been compared to the Malaysian Interim National Water Quality 

Standards (INWQS) in order to make a classification of the water quality of the 

different zones of the river. The INWQS operates six classes of water quality: 

Class I, representing water bodies of excellent quality, most suitable for 

water extraction for human consumption. This type of water is typically encountered 

in uninhabited areas without antropogenic discharge. Very sensitive 

aquatic species thrive in Class I waters; 

Class IIA, representing water bodies of good quality. Most existing raw water 

supply sources in Sarawak come under this category. Conventional low 

cost treatment required; 

Class IIB water, which is suitable for recreational use with body contact. If 

used for water supply for human consumption, excessive treatment is required 

which incurs relatively high costs; 

53


Class III, representing polluted water. The class is used primarily to protect 

common and moderately tolerant aquatic species of economic value. Water 

under this classification may be used for water supply with extensive/advanced 

treatment; 

Class IV, representing heavily polluted water which must only be used for 

irrigation purposes; and 

Class V, representing heavily polluted water, which must not even be used 

for irrigation purposes. 

The concentration limits for pollutants in the different classes of water quality 

are stipulated in DOE, 1993. Selected values are presented in Table 5.5. 

A classification according to the INWQS of the different zones of the Sg. Sarawak 

system based on the 1999 and 2000 data is presented below. 

Table 5.5 Selected water quality parameters used in the classification under 

the DOE Interim National Water Quality Standards for Malaysia. 

Parameters Class 

I 

Class 

IIA 

Class 

IIB 


Class 

III 

Class 

IV 

Class 

V 

NH4-N (mg/l) 0.1 0.3 0.3 0.9 2.7 >2.7 

BOD (mg/l) 1 3 3 6 12 >12 

COD (mg/l) 10 25 25 50 100 >100 

DO (mg/l) 7 5-7 5-7 3-5 < 3 < 1 

TSS (mg/l) 25 50 50 150 300 >300 

Faecal Coliforms * 10 100 400 5000 5000 

(counts/100ml) 

(20,000) (20,000) 

Total Coliforms 

(counts/100 ml) 

100 5000 5000 50,000 50,000 >50,000 

* Geometrical mean. Values in parentheses must not be exceeded 

Zone A (Sg. Sarawak Kanan) 

The data from Sg. Sarawak Kanan are summarised in Tables 1-2 in Appendix 

1. Mean concentrations of selected parameters are presented in Table 5.6. 

The water quality of Sg. Sarawak Kanan is quite good in terms of physicochemical 

parameters (DO, BOD, COD, TSS, Turbidity and Ammoniacal- 

Nitrogen etc). In general, these parameters comply with Class IIA/IIB limits. 

However, the water does not meet the class IIA/IIB standards for coliform bacteria, 

which is probably due to discharge of untreated domestic wastewater 

from the riverine communities, including Bau and Siniawan areas. 

54


Table 5.6 Mean concentrations of selected water quality parameters in Zone 

A (Sg. Sarawak Kanan). Wet season: Nov-Feb. Dry season: Mar-Oct. 

Parameter Wet Season 

1999 

Dry Season 

1999 

Wet Season 

2000 


Dry Season 

2000 

INWQS 

class IIB 

No samples 6 18 6 18 

NH4-N (mg/l) 0.1 0.1 0.08 0.1 0.3 

BOD (mg/l)


Zone C (Sg. Sarawak Proper from Batu Kawa Bridge to upstream Satok 

Bridge) 

In general the water quality values in zone C complies with class IIA/IIB. The 

average Total Coliform levels are however marginally higher than the Class IIB 

limits (Table 5.8, Tables 5-6 in Appendix 1). 


C (main Sg. Sarawak from Batu Kawa Bridge to upstream of Satok Bridge). 

Wet season: Nov-Feb. Dry season: Mar-Oct. 


1999 

Dry Season 

1999 

Wet Season 

2000 


Dry Season 

2000 

56 

INWQS 

class IIB 


NH4-N (mg/l) 16,000 5,000


Tributaries in Kuching 

The water qualities in the tributaries Sg. Maong (Zone E), Sg. Bintangor (Zone 

F) Sg. Padungan (Zone G), Sg. Sekama Zone (H) and Sg. Tabuan (Zone I) are 

very poor and fall between class IV/V (Tables 5.10-5.14 and Tables 9-10 in 

Appendix 1). 


E (Sg. Maong). Wet season: Nov-Feb. Dry season: Mar-Oct. 


1999 

Dry Season 

1999 

Wet Season 

2000 


Dry Season 

2000 

57 

INWQS 

class IIB 


NH4-N (mg/l) 2.2 4.6 2.0 4.7 0.3 

BOD (mg/l) 9.6 11.9 3.6 6.0 3 

COD (mg/l) 35.2 37.5 27.0 32.3 25 

DO (mg/l) 1.3 1.4 2.6 0.8 5-7 

TSS (mg/l) 15.6 17.5 12.0 27.8 50 

Faecal coliforms 


>16,000 >16,000 >16,000 >16,000 400 

Total coliforms 


>16,000 >16,000 >16,000 >16,000 5,000 


F (Sg. Bintangor). Wet season: Nov-Feb. Dry season: Mar-Oct. 


1999 

Dry Season 

1999 

Wet Season 

2000 

Dry Season 

2000 

INWQS 

class IIB 

No samples - - 2 10 

NH4-N (mg/l) - - 1.7 3.1 0.3 

BOD (mg/l) - - 3.6 5.6 3 

COD (mg/l) - - 11.4 25.4 25 

DO (mg/l) - - 2.2 2.4 5-7 

TSS (mg/l) - - 19.5 39.7 50 



- - >16,000 >16,000 400 



- - >16,000 >16,000 5,000



G (Sg. Padungan). Wet season: Nov-Feb. Dry season: Mar-Oct 


1999 

Dry Season 

1999 

Wet Season 

2000 


Dry Season 

2000 

58 

INWQS 

class IIB 


NH4-N (mg/l) - - 4.2 3.2 0.3 

BOD (mg/l) - - 3.9 5.8 3 

COD (mg/l) - - 23.6 31.8 25 

DO (mg/l) - - 1.9 2.2 5-7 

TSS (mg/l) - - 24 46.6 50 


(MPN/100ml) 

- - >16,000 >16,000 400 



- - >16,000 >16,000 5,000 


H (Sg.Sekama). Wet season: Nov-Feb. Dry season: Mar-Oct 


1999 

Dry Season 

1999 

Wet Season 

2000 

Dry Season 

2000 

INWQS 

class IIB 


NH4-N (mg/l) - - 1.2 2.2 0.3 

BOD (mg/l) - - 3.1 4.5 3 

COD (mg/l) - - 14.7 22.5 25 

DO (mg/l) - - 3.3 2.9 5-7 

TSS (mg/l) - - 44.5 39.6 50 



- - >16,000 >16,000 400 



- - >16,000 >16,000 5,000



I (Sg. Tabuan. Wet season: Nov-Feb. Dry season: Mar-Oct 


1999 

Dry Season 

1999 

Wet Season 

2000 


Dry Season 

2000 

59 

INWQS 

class IIB 

No samples 54 54 - - 

NH4-N (mg/l) 2.6 2.9 - - 0.3 

BOD (mg/l) 19.9 14.5 - - 3 

COD (mg/l) 73.7 94.2 - - 25 

DO (mg/l) 0.9 1.4 - - 5-7 

TSS (mg/l) 19.0 37.0 - - 50 



- - - - 400 



- - - - 5,000 

Overview 

The water qualities of different zones classified according to the Malayisan Interim 

National Water Quality Standards (INWQS) is summarised in Table 5.15 

Table 5.15 Summary of INWQS classification of the different zones of the Sg. 

Sarawak system. 

Zone DOE INWQS Class 

Physical-chemical 

parameters 

Zone A (Sg. Sarawak Kanan) IIA/IIB 

Zone B (Sg. Sarawak Kiri) IIA/IIB 

Zone C (Sg. Sarawak main from Batu 

Kawa to upstream Satok bridge) 

Zone D (Sg. Sarawak main from Satok 

Bridge to downstream of barrage) 

DOE INWQS Class 

Bacteriological parameters 

IIA/IIB III 

III V 

Zone E (Sg. Maong) IV/V V 

Zone F (Sg. Bintangor) IV/V V 

Zone G (Sg. Padungan) IV/V V 

Zone H (Sg. Sekama) IV/V V 

Zone I (Sg. Tabuan) IV/V V 

5.2.3 Change in Water Quality 

Historical data from DOE indicates that the water quality of Sg. Sarawak declined 

during the period of 1987-1997 prior to the establishment of the barrage, 

mainly due to increased concentration of suspended solids and ammoniacal nitrogen 

(Memon and Murtedza, 1999).


5.3 Sediment Quality 

The assessment of the sediment quality of Sg. Sarawak focuses on parameters, 

which have been chosen as preliminary indicators for sediments in the EMS for 

Kuching i.e.: 

Nutrients (Ammoniacal Nitrogen, Nitrate, Total Nitrogen, Phosphorus); 

Heavy Metals (Hg, Pb, As, Zn, Cd, Cr, Cu, Fe, Ni, CN, Mn); 

Polyaromatic hydrocarbons (PAH) and Total Petroleum Hydrocarbon 

(TPH); and 

Oil & Grease. 

Evaluation of the present sediment quality is based on studies performed by the 

SUD Project in November 2000 (Sg. Sarawak) and July 2001 (Sg. Kuap) and 

by a research group from UNIMAS and the Geological Survey Malaysia (Lau 

Seng et al, 1995 and Lau Seng et al, 1998). 

5.3.1 SUD Field Study of Sg. Sarawak 

The findings of the SUD field study on sediment pollution in Sg. Sarawak conducted 

in November 2000 are reported in detail in the Volume 3 of the River 

Quality Baseline Study Report. The locations of sampling sites are presented in 

Figure 5.4 

The SUD field study clearly indicates that pollutants from outlets in Kuching 

were accumulated in the sediments of Sg. Sarawak. The major findings in terms 

of composition of sediments (which is important for the interpretation of the 

data on pollutants) and the accumulation of different types of pollutants are 

presented below. 


60


Fig 5.4. Sampling locations for sediments in Sg. Sarawak in November 2000 


61


Composition of sediment 

The sediment mainly consists of clay and silt along the stretch of Sg. Sarawak 

from S1, upstream of Sg. Maong to S6, downstream of Petanak (Fig. 5.5). Further 

downstream, the sand content increase markedly to S8 at Pending, where 

as much as 76% of the sediment consist of sand particles. Downstream of the 

barrage at S9, fine grained sediment predominates again. The sandy sediment at 

S7 and S8 is probably a result of the flushing procedure at the barrage. During 

flushing, the fine-grained particles of the sediment are suspended and transported 

downstream of the barrage where they resettled. 

% 

120 

100 

80 

60 

40 

20 

0 

Composition of sediment 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Figure 5.5. Composition of sediments at the sampling stations. (The locations 

of sampling sites are presented in Fig 5.4) 

Organic matter and nutrients 

Organic matter from the outlets in Kuching clearly accumulates in the sediments 

of Sg. Sarawak. This is indicated by the concentration patterns of loss on 

ignition (which is a measure of the content of organic matter), Total N, Total P 

and NH4-N observed at the monitoring stations (Fig. 5.6, Fig. 5.7 and Fig. 5.8). 

The loss on ignition, which is a measure of the content of organic matter and 

the concentrations of Total N and total P, increases from upstream of Kucing 

(S1) to Sg. Bintangor (S4). From S4, a gradual decrease is observed and at Kg 

Bintawa (S7), the levels have dropped to levels comparable to those encountered 

upstream of Kuching (Fig 5.6 and 5.7). The decrease from S4 and further 

downstream is probably primarily the result of the flushing procedure at the 

barrage. 

NH4-N increases dramatically from station S1 upstream of Sg. Maong to S2, 

downstream of Sg. Maong from where a gradual decrease is observed to almost 

undetectable levels a S7 at Kp Bintawa. (Fig.5.8). NH4-N in the sediment arises 


Station 

Sand, % Silt+clay % 

62


from the degradation of nitrogenous organic matter. In aerobic environments, 

NH4-N is oxidised to nitrite and further to nitrate. The fact that the highest levels 

of NH4-N are encountered at S2 and S3 indicates poorer oxygen conditions 

in the sediments at these stations compared to further downstream. Improved 

oxygen conditions further downstream may be an effect of the flushing at the 

barrage, bringing oxygen rich water into the river. 

Figure 5.6. Loss on ignition of sediments in Sg. Sarawak in November 2000. 

(The locations of sampling sites are presented in Fig 5.4) 

mg/kg 

% 

14 

12 

10 

8 

6 

4 

2 

0 

3000 

2500 

2000 

1500 

1000 

500 

0 

Loss on ignition 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Figure 5.7. Concentrations of total N and P in sediments in Sg. Sarawak in November 

2000. (The locations of sampling sites are presented in Fig 5.4). 


Station 

Total N and P in sediments 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Station 

Tot-N Tot-P m 

63


200 

180 

160 

140 

120 

mg 

/kg 

100 

80 

60 

40 

20 

0 

NH4-N in sediment 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Figure 5.8. Concentrations of total NH4-N in sediments in Sg. Sarawak in November 

2000 (The locations of sampling sites are presented in Fig 5.4). 

Heavy metals 

The results of the SUD study in November 2000 also clearly show that heavy 

metals from outlets in Kuching are accumulated in the river sediments. 

The heavy metal concentrations gradually increase from S1 upstream of the 

confluence of Sg. Maong to maximum levels at S4, off Sg. Bintangor and S5 at 

Holiday Inn. From S5, a gradual decrease of heavy metals is observed to the 

downstream location S9, off the Barrage (Figures 5.9-5.12). 

This pattern is observed for Pb, Cu, Ni, Cd, Zn, Cr. and Fe. The concentrations 

of Mn and Hg do not increase to any appreciable extent downstream of S1, indicating 

that the City of Kuching is not a major source of Mn and Hg pollution. 

The decreasing concentration of heavy metals from Petanak (S6) to Pending 

(S8) is probably an effect of the flushing procedure at the barrage. It is evident 

from the results of the grain size analysis that the sediment becomes more 

sandy around Pending compared to further upstream, indicating that the finer 

grained fractions to which heavy metals are mainly adhered/absorbed, are 

flushed out to sea. 


Station 

64


mg 

/kg 

Figure 5.9. Concentrations of copper (Cu), lead (Pb), nickel (Ni), chromium 

(Cr) and arsenic (As) in sediments in Sg. Sarawak in November 2000 (The locations 

of sampling sites are presented in Fig 5.4). 

mg/kg 

25 

20 

15 

10 

5 

0 

1 

0,9 

0,8 

0,7 

0,6 

0,5 

0,4 

0,3 

0,2 

0,1 

0 

Heavy metals in sediment 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Figure 5.10. Concentrations of Cadmium (Cd) and mercury (Hg) in sediments 

in Sg. Sarawak in November 2000 (The locations of sampling sites are presented 

in Fig 5.4). 


station 

Cu Pb Ni Cr As 

Cadmium and mercury in sediment 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Station 

Cd Hg 

65


mg/kg 

Figure 5.11. Concentrations of zinc (Zn) and manganese (Mn) in sediments in 

Sg. Sarawak in November 2000 (The locations of sampling sites are presented 

in Fig 5.4). 

mg/kg 

350 

300 

250 

200 

150 

100 

50 

0 

30.000,00 

25.000,00 

20.000,00 

15.000,00 

10.000,00 

5.000,00 

0,00 

Zinc and manganese in sediment 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Figure 5.12. Concentrations of iron (Fe) in sediments in Sg. Sarawak in November 

2000 (The locations of sampling sites are presented in Fig 5.4). 

In order to assess the potential adverse biological effects due to heavy metals in 

the sediment, the results have been compared to recently developed Canadian 

Sediment Quality Standards which relates sediment chemistry data to the potential 

for adverse biological effects (CCME, 1999). 

Based on a considerable number of studies on the correlation between concentration 

and toxicity, a Probable Effect Level (PEL) was established for a wide 

number of pollutants in sediments. Concentrations equivalent to and above PEL 

represents concentrations, which are likely to cause adverse biological impacts. 


Station 

Zn Mn 

Iron in sediments 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Station 

66


Hg is found above the PEL level on all sampled sites in Sg. Sarawak. Consequently, 

there may be a risk of adverse biological impacts due to Hg (Cf. Table 

5.16). The main source of Hg is however, not the City. Toxic levels are already 

encountered upstream of Kuching. The source may be mining activities upstream 

(Cf. section 5.3.2). 

The concentrations of the other heavy metals are below PEL and are therefore, 

not expected to cause any adverse impacts on organisms. 

Table 5.16 Concentration of heavy metals in sediment collected in November 

2000 in Sg. Sarawak (mg/kg dry weight). The Canadian Probable Effects 

Level (PEL) for the different metals are also shown. Figures in bold exceed 

the PEL. 


Cu 

ppm 

Pb 

ppm 

S1 Upstream Maong 10 10.2 48.6 0.44 3.8 0.73 6.9 

S2 Downstream Maong 14.7 17.4 106.0 0.54 4.9 0.92 4.5 

S3 Satok bridge 17.6 21.9 131.0 0.63 6.3 0.84 11.6 

S4 Bintangor 17.2 22.5 140.0 0.61 6.8 0.81 10.6 

S5 Holiday inn 17.5 23.3 134.0 0.63 7.1 0.93 6.5 

S6 Petanak 15.0 20.9 100.0 0.52 9.4 0.62 10.7 

S7 Kp Bintawa 12.3 14.9 82.9 0.41 4.2 0.77 4.9 

S8 Pending 4.1 6.9 26.9 0.34 3.7 0.64 9.2 

S9 Downstream barrage 4.8 9.0 32.4 0.37 4.8 0.63 6.3 

PEL 197.0 91.3 315.0 3.5 90.0 0.49 17.0 

Pesticides 

Pesticides were not found in any of the sediment samples. All pesticides analysed 

were below the detection limits (0.001 mg/kg for organochlorinated pesticides 

(0.005 mg/kg for chlordane) and 0.01 mg/kg for organophosphorated 

pesticides. 

Petroleum hydrocarbons 

Polyaromatic Hydrocarbons PAHs were also not found. All individual PAHs 

analysed for were below the detection limit of 0.1 mg/kg. 

Elevated concentrations of Total Petroleum Hydrocarbons (TPH) compared to 

upstream of Kuching were encountered at Satok Bridge (S3) and Sg. Bintawa 

(S7) (Fig. 5.13). 

Zn 

ppm 

Cd 

ppm 

Cr 

ppm 

Hg 

ppm 

As 

Ppm 

67


mg/kg (C15-C36) 

350 

300 

250 

200 

150 

100 

50 

0 

TPH in sediments 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Figure 5.13. Concentrations of Total Petroleum Hydrocarbons (TPH) in sediments 

in Sg. Sarawak, November 2000. The locations of sampling sites are presented 

in Fig 5.4) 

5.3.2 SUD Field Study Sg. Kuap 

The findings of the SUD field study on sediment pollution in Sg. Kuap conducted 

in July 2001 are reported in detail in the Volume 3 of the River Quality 

Baseline Study Report. The sampling locations are indicated in Fig. 5.14. 

The study clearly indicates that heavy metals from the Sama Jaya Free Industrial 

Zone are accumulated in the sediments of Sg. Kuap. 

The concentrations of heavy metals increase markedly from upstream of the 

industrial estate to the area off the estate. Further downstream, a slight decrease 

is observed for most metals (Figs 5.15-5.17). This pattern indicates that the industrial 

estate is a source contributing heavy metals to the sediments. 

Although heavy metals are accumulated in the sediments, the concentrations 

are below levels, which are likely to be toxic to aquatic organisms. The concentrations 

are below the Canadian Probable Effect Levels (Cf. Table 5.17). 

Similar to Sg. Sarawak, pesticides were not found in any of the sediment samples 

from Sg. Kuap. All pesticides analysed were below the detection limits. 


Station 

68


N 

Fig 5.14. Sampling locations for sediments in Sg. Kuap and Sg. Sarawak in 

July 2001. The Red box indicate the Samajaya Free Industrial Zone. 


SD1 

SD2 

SD4 

SD3 

69


mg/kg 

Figure 5.15. Concentrations of copper (Cu), lead (Pb) nickel (Ni), chromium 

(Cr) and arsenic (As) in sediments in Sg. Kuap July 2000. 

mg/kg 

30 

25 

20 

15 

10 

5 

0 

0,9 

0,8 

0,7 

0,6 

0,5 

0,4 

0,3 

0,2 

0,1 

0 

SD4 SD3 SD2 

Cu Pb Ni Cr As 

SD4 SD3 SD2 

Figure 5.16. Concentrations of cadmium (Cd) in sediments in Sg. Kuap July 

2000. 


70


mg/kg 

140 

120 

100 

80 

60 

40 

20 

0 

Figure 5.17. Concentrations of zinc (Zn) in sediments in Sg. Kuap July 2000. 

Table 5.17 Concentration of heavy metals in sediment collected in July 2000 

in Sg. Kuap (mg/kg dry weight). The Canadian Probable Effects Level (PEL) 

for the different metals are also shown. 


Cu 

ppm 

Pb 

ppm 

Zn 

SD4 SD3 SD2 

SD4 Upstream 0.8 3.0 6.6 0.24 2.00 5.3 

SD3 28.0 27.8 121.0 0.78 7.4 0.03 

SD2 10.3 23.5 72.9 0.83 20.9 2.1 

PEL 197.0 91.3 315.0 3.5 90.0 17.0 

5.3.3 Previous Research Studies 

All results from the previous research studies carried out by the research group 

from UNIMAS and the Geological Survey Malaysia is summarised in Table 

5.18. Sampling sites are indicated on Figure 5.18 and 5.19. 

Zn 

ppm 

Cd 

ppm 

Cr 

ppm 

As 

ppm 

71


Figure 5.18. Sediment sampling sites. S1= upstream of confluence of Sg. Sarawak 

and Sg. Maong. S2= Downstream of the confluence of Sg. Sarawak and 

Sg. Maong. S3= At the Satok Bridge. S4= Off Sg. Bintangor. S5= Off Holiday 

Inn. S6= Off Kuching Port Authority. S7=Off tributary west of Kp Bintawa. 

S8= Off Pending. S9=Downstream of the Barrage. 


72


Figure 5.19. Sediment sampling sites. 


73



The concentrations of heavy metals in the sediments of Sg. Sarawak Kiri was 

generally very low, in many cases below the detection limit and all cases below 

levels which may be toxic to sensitive organisms. However, high concentrations 

of iron were encountered. 

As described in section 5.2.1, this is not related to human activities, as high 

background concentrations of iron are to be expected in the river system. 

Sg. Sarawak Kanan 

The contents of heavy metals in the sediments of Sg. Sarawak Kanan were significantly 

higher than in Sg. Sarawak Kiri. Very high and toxic concentrations 

of As and Hg were encountered. The concentrations of Cd, Cr and Pb were also 

quite high. The study indicates that the source of these metals is located between 

Bau and Buso where previous gold mining activities and quarry operations 

has taken place (Fig 5.20). The polluted sediments will gradually be 

transported downstream and may affect the sediments in the part of the river 

running through Kuching. 


74



As 

ppm 

Table 5.18 Heavy metals in sediments in the Sg. Sarawak system found by 

UNIMAS and the Geological Survey Malaysia. (- = not measured; nd = not 

detected). The Canadian Probable Effects Level (PEL) for the different metals 

are also shown. Figures in bold exceed the PEL. 

Cd 

ppm 

Cr 

ppm 


Cu 

ppm 

Padawan


mg/kg 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

Bau Buso Kp Keranji Batu Kawa Muara Tebas 

As Hg 

Figure 5.20. Concentration of As and Hg in sediments of Sg. Sarawak Kanan 

(Bau, Buso and Kp Keranji) and Sg. Sarawak Main (Batu Kawa and Muara 

Tebas) found by Lau Seng et al 1995. 

Sg. Sarawak Proper 

The studies show that concentrations of heavy metals increase between Batu 

Kawa and Muara Tebas, which are in accordance with the SUD study. 

Sg. Maong 

The concentration of heavy metals in Sg. Maong was significantly higher than 

those found in Sg. Sarawak (compare Table 5.16 and 5.18). Potentially toxic 

levels of Cd, Pb and Zn were encountered in Sg. Maong. 

5.4 Accumulation of Pollutants in Organisms 

Following the discovery that sediments were polluted by heavy metals from 

gold mining and quarry operations in the Bau areas, the research group from 

UNIMAS and Geological Survey Malaysia carried out a study on accumulation 

of heavy metals in freshwater molluscs (Lau Seng et al. 1998). Sediment samples 

and freshwater molluscs (Clithon sp., Brotia costula and Melanoides tuberculata) 

were collected at the same sites and analysed for heavy metals 

The molluscs obviously accumulated As, Cu and Zn from the sediments and the 

results clearly indicated that the heavy metal source was Sg. Bau. Figure 5.21 

shows an example (Concentration of Arsenic in sediments and the molluscs 

Clithon sp. and Brotia costula). 

All the molluscs collected from the study area were found contaminated with 

As and the levels of Cu and Zn were at the maximum concentration allowable 

for seafood as stipulated by the Food Act (1983). Levels of Cd, Hg and Pb were 

however low in the molluscs tissues collected for the study. 


76


There are no data from the river system in the Kuching area. 

mg As/kg dry wt. 

60 

50 

40 

30 

20 

10 

0 

Figure 5.21. Concentration of Arsenic in sediment and two freshwater molluscs 

(Brotia costula and Melanoides tuberculata) upstream and downstream of 

heavy metal sources at Sg. Bau. 

5.5 Ecosystem Impacts 

ST 1 upstream ST 3 downstream 

Sediment Brotia Cliton 

In order to be able to assess the impacts of the pollution of the river on aquatic 

organisms, a pilot study on benthic macroinvertebrates was carried out by the 

SUD Project in November 2000 in connection with the sediment study. 

Benthic macroinvertebrates (benthos) in the lower reaches of rivers and in the 

sea are from a wide variety of species of mainly oligochaete and polychaete 

worms, mussels, snails, starfish, sea urchins and crustaceans living in burrows 

in the sediment or on the sediment surface. 

Benthos samples were collected at the same time and at the same sites as the 

sediment samples (Cf. Fig 5.4) in order to be able to relate sediment contamination 

impacts on benthic fauna. 

The findings of the SUD field study on sediment pollution in Sg. Sarawak conducted 

in November 2000 are reported in detail in the Volume 3 of the River 

Quality Baseline Study Report. The major findings are presented below. 

Composition of fauna 

Oligochaete worms dominates the fauna in Sg. Sarawak upstream of the barrage. 

Tubificidae worms are the most common, with Tubifex occurring as the 

most common genus. Downstream of the barrage oligochates were absent and 

marine molluscs dominate the fauna. 


77


Diversity index 

The diversity and species richness of macrobenthos generally show an increase 

downstream from S1 to S10 (Fig 5.22). 

Diversity Index (H') 

Species Richness (R1) 

4 

3,5 

3 

2,5 

2 

1,5 

1 

0,5 

0 

S1 S2 S3 S4 S5 S6 S7 S8 S9 

Station 

Shannon Weaver Diversity Index Margalef Richness Index 

Figure 5.22. Diversity index (H`=Shannon Wiener index) and species richness 

(R1= Margaleffs index) at each sampling site. For calculations of these reference 

is made to Volume 3 of the river quality baseline study. The locations of 

sampling sites are presented in Fig 5.4.No organisms were encountered at S5 

due to hard substrate on which the sampler did not function. 

Environmental factors affecting the fauna 

There are strong indications that the organic matter discharged from Kuching 

affects the benthos, upstream of the barrage. 

Based on a substantial amount of data, Pearson & Rosenberg (1978) found a 

general succession pattern of benthic infauna in response to increased input of 

organic material to the sediment: 

Initially increasing input of organic matter will result in an increase in the 

number of species, the biomass and the density (abundance) of organisms 

because the amount of food for organisms increases (many benthic species 

feed on organic matter on the seabed); 

When the input reaches a certain level, the number of species and, the biomass 

and the density decline. The reason behind this is that the oxidised 

layer of the sediment becomes thinner because the organic matter consumes 

oxygen; 


78


At very heavy loads, oxygen depletion in the sediment may periodically 

take place. Only very few species can tolerate in such conditions. As a result, 

the numbers of species decrease further. Longer periods of oxygen depletion 

lead to the extinction of the fauna. In case of oxygen conditions 

have improved, the area will be re-colonised rapidly by a very few known 

as opportunistic species, which may be found in high densities. 

The benthos data from Sg. Sarawak can be interpreted in the context of the 

Pearson & Rosenberg succession of benthos in relation to increasing organic 

load. 

Abundance (number of individuals) and number of species of benthos are compared 

to the content of organic matter in the sediment (measured as loss on ignition) 

in Figure 5.23. 

It is evident that the abundance of species and the number of species increase 

concurrently with an increase in the content of organic matter when moving 

from Pending (S8) and upstream to Petanak (S6) and off Sg. Bintangor (S4). 

This is probably as a result of increasing amount of food in the form of organic 

matter. 

At the Satok Bridge (S3) and downstream of Maong (S2), the abundance and 

number of species drop dramatically despite the fact that the organic contents 

are similar to S6 and S4. The drop is probably an effect of poor oxygen conditions 

in the sediment. High levels of NH4-N are thus encountered here indicating 

poor oxygen conditions (Fig 5.24). The relatively better oxygen conditions 

further downstream at S4 and S6 may be an effect of the flushing at the barrage, 

bringing oxygen rich water into the river. 

This interpretation is strongly supported by the fact that the fauna is completely 

dominated by species of Oligochaete worms and that the changes in abundance 

and number of species described above is largely changes in abundance and 

number of species of Oligochaetes. Oligochaetes have been recognised as bioindicators 

for organic pollution (Canfield et al 1994, 1996). They are deposit 

feeders, subsisting on organic detritus and its associated microflora feeding on 

detritus in the sediment. Generally, they can tolerate quite low oxygen concentrations 

and may be found in large numbers in organical polluted habitats. 


79


individuals/m3 

number 

1800 

1600 

1400 

1200 

1000 

7 

6 

5 

4 

3 

2 

1 

0 

800 

600 

400 

200 

0 

S8 S7 S6 S4 S3 S2 S1 

Station 

Abundance LOI, % 

S8 S7 S6 S4 S3 S2 S1 

Station 

No species LOI, % 

Figure 5.23. Abundance (number of individuals) and number of species of benthos 

compared to the content of organic matter in the sediment (measured as 

loss on ignition). The locations of sampling sites are presented in Fig 5.4. 


14 

12 

10 

8 

6 

4 

2 

0 

14 

12 

10 

8 

6 

4 

2 

0 

% Loss on ignition 

% Loss on ignition 

80


individuals/m3 

Number of species 

1800 

1600 

1400 

1200 

1000 

7 

6 

5 

4 

3 

2 

1 

0 

800 

600 

400 

200 

0 

Figure 5.24. Abundance (number of individuals) and number of species of benthos 

compared to the content of NH4-N in the sediment. The locations of sampling 

sites are presented in Fig 5.4. 

The higher diversity and species richness at S9 downstream of the barrage is 

probably due to the fact that the salinity in this area is higher. The fauna is being 

dominated by the presence of marine molluscs and bivalves. Higher species 

diversity is generally encountered in more saline waters compared to more 

brackish waters. 

5.6 Floating Debris 

S8 S7 S6 S4 S3 S2 S1 

Station 

Abundance NH4-N 

S8 S7 S6 S4 S3 S2 S1 

Station 

No species NH4-N 

The presence of floating debris is aesthetically unpleasant and presents a hazard 

to river travel. In a study carried out by DHV Consultants in Nov/Dec 1990 and 

Jan/Feb, a generation of floating waste was estimated at 18,800 – 22,000 


200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

200 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

mg/kg NH4-N 

mg/kg NH4.-N 

81


m 3 /year. DBKU has the yearly measurements of the volume of floatables. The 

amount of floatables has decreased from some 125,000 m 3 /year in 1994 to 

45,000 m 3 /year in 1999 (Figure 5.25). The DHV study estimated the composition 

of floating debris as follows: 

About 80% of the debris were river and river bank vegetation (bamboo, nipah 

palm cut-offs, water hyacinth, branches and logs); 

About 15 % were wood waste (tree branches, logs, sawdust, sawn timber 

planks and off cuts); and 

About 5 % were municipal solid waste (plastic bottles and containers, plastic 

bags, steel and aluminium cans, paper/cardboard packaging, polystyrene 

foam, aerosol cans, etc.). 

Another study carried out by KTA (Sarawak) Sdn Bhd in 1997 confirmed that 

majority of the floatables found in Sg. Sarawak were still bamboo and vegetation. 

However, inspection by boat used during the study revealed that the proportion 

of wood waste appeared to be greater than the previously determined of 

m3 floatables 

15%. 

140000 

120000 

100000 

80000 

60000 

40000 

20000 

0 

year 1994 year 1995 year 1996 year 1997 year 1998 year 1999 

Figure 5.25. Amount of floatables (m 3 ) collected by DBKU on Sg. Sarawak. 

1994-1999. 


82


6 Sources of Pollution and Pollution load 

6.1 Overview of Pollution Sources 

Sg. Sarawak and its main tributaries are receiving large amounts of sewage and 

wastewater from a wide variety of sources both from Kuching and upstream of 

Kuching. 

At the SUD workshop on Preliminary Goal setting in November 1999, the possible 

sources of pollutants to the river were identified (reported in SUD report 

“Preliminary goals, targets and indicators for sustainable urban development in 

Couching Sawara (SUD-02-03, SUD-02-07). The major sources were identified 

as: 

Households; 

Food outlets including markets, restaurants and coffee shops; 

Small and Medium Industries (SMI) and Large Scale Industries (LSI); 

Agriculture; and 

River vessels. 

The pollutants generated from these activities were identified during the workshop 

(Table 6.1). The amounts of wastewater and contaminants were not quantified 

during the workshop. Previously, there has been no attempt to estimate 

the pollution load from different sources in Kuching. During the baseline study, 

the first attempt to quantify load from different sources were made. Details on 

the estimation of pollution load from different sources are presented in Volume 

2 of the River Quality Baseline Study Report and the major findings are presented 

in the following sections. 


83


Table 6.1 Factors affecting the Sarawak River quality. 

Upstream based 

sources 

Kuching based 

sources: 

Source Pollutants 

Agriculture, including live- 

stock 


Faecal and total coliforms 

Nutrients (especially N and P) 

BOD 

COD 

Pesticides 

Mining Cyanide 

Food outlets and house- 

holds 

Industries 

(A detailed outline of pol- 

lutants from different types 

of SMIs and LSIs is pre- 

sented in Table 6.8) 

Mined minerals and metals (Hg, As etc.) 

Faecal and total coliforms 

Nutrients(especially N and P) 

BOD 

COD 

Suspended solids 

Grease and oil 

Heavy metals 

Oil and grease 

Other inorganic substances and compounds 

Organic compounds, such as organic solvents, 

residue from industrial processes and products 

Micro organisms 

COD, BOD, AOX 

Vessels Heavy metals 

Organic solvents 

Oil spills 

Types of pollutants, discharge, treatments facilities, number of sources as well 

as estimated loads from households, food outlets and industries are described in 

sections 6.2, 6.3 and 6.4 below. Pollution from agriculture and other sources are 

described in sections 6.5 and 6.6. 

6.2 Pollution from Households 

6.2.1 Types of Pollutants from Households 

Domestic sewage can be separated into blackwater, which is body wastes (faeces 

and urine) and greywater, and all other liquid wastes of the household, including 

laundry, bathroom/washroom and kitchen wastewater. Body wastes are 

the most hazardous due to the possibility of contact with intestinal disease organisms. 

Greywater has fewer disease organisms unless the laundry has contained 

garments soiled by faecal discharges. 

The most significant pollutants in grey- and blackwater which have been chosen 

as indicators for pollution from households are ammoniacal nitrogen, phosphorous, 

BOD, COD, faecal coliforms, total coliforms and TSS. 

84


6.2.2 Estimated Population and Number of Households 

The SUD Project has estimated the population size and the number of different 

types of houses in the twelve catchment areas, which are discharging to Sg. Sarawak 

upstream of the barrage (Cf. Fig. 4.3 in section 4.1). Details are presented 

in Volume 2 of the River Quality Baseline Study Report. In year 2000, a 

total population of 215,000 people living in about 26,000 houses was identified 

in these catchment areas. The most important residential areas being (Table 

6.2): 

1. The Maong sub-catchment area with 94,192 inhabitants; 

2. Padungan (15,619 inhabitants); 

3. Bintawa 1 (11,901 inhabitants); 

4. Seman Lama (11,485 inhabitants); and 

5. Sinjan (10,641 inhabitants). 

Not included in these estimates is a residential area in the catchment of Sg. 

Kuap (mainly around Sg. Tabuan). The population in this area has been estimated 

at about 100,000 (SPU, 1998). 


85


Table 6.2 Population and numbers of different types of Households in different 

Sub-catchment areas. Locations of the sub-catchment areas are shown on 

Fig 4.3 Section 4.1. 

Catchment Popu- 

South of Sg. 

Sarawak 

lation 


De- 

tached 

houses 

Semi- 

detached 

houses 

Terrace 

houses 

Flats Kam- 

pung 

houses 

Total 

house- 

Bintangor 1 4,402 136 28 - - 131 295 

holds 

Bintangor 2 6,645 176 140 176 250 336 1078 

Bintangor 3 5,749 14 - 14 102 52 182 

Padungan 15,619 512 250 1,596 670 - 3028 

Sekama 3,513 65 86 194 - - 345 

Sekama 1 2,253 64 32 82 - - 178 

Periok 741 55 20 10 - - 85 

Biawak 2,810 - - 100 144 - 244 

Bintawa 1,601 - - - - - - 

Bintawa 1 11,901 32 152 605 - - 789 

Kudei 8,151 64 223 1,102 - 96 1485 

Maong 94,192 3,150 3,208 4,944 1,186 - 12,488 

North of Sg. 

Sarawak 

Gita 8,937 69 188 346 - - 603 

Laruh 5,975 139 290 409 - - 838 

Turong 1,356 30 12 28 - 141 211 

Sinjan 10,641 196 78 578 - 390 1242 

Bedil 9,167 - - - - 801 801 

Gersik 2,504 - - - - 258 258 

Seman Lama 11,487 - - - - 1719 1719 

Siol Kandis 1 7,489 2 450 - - 23 475 

Siol Kandis 2 558 85 - - - - 85 

Total 215,664 4,789 5,157 10,184 2,352 3947 26,429 

6.2.3 Treatment Facilities and Draining Systems 

Greywater 

Almost all houses in Kuching discharge untreated greywater directly into the 

stormwater drains in the city. The stormwater drain is an extensive open channels 

system which discharges into smaller tributaries (Sg. Maong, Sg. Bintangor, 

Sg. Padungan, Sg. Sekama etc) or directly to Sg. Sarawak. 

The only measure to reduce contaminants from entering the drains is the usage 

of coarse filtering equipment installed at washing sinks. 

86


Blackwater 

Houses are generally equipped with individual septic tanks for the treatment of 

blackwater. Then, the effluent from the septic tanks discharge to the drains and 

then to the river. 

Septic tank serve as a combined settling and skimming tank and an anaerobic 

digester, which decompose organic matter. 

Heavier solids from the incoming wastewater settle and form a sludge layer at 

the bottom of the tank. Grease and other light materials float on the surface 

where a scum layer is formed as floating materials accumulated. 

The organic material retained in the bottom of the tank undergoes anaerobic 

decomposition and is degraded to more stable compounds and gases such as 

carbon dioxide (CO2), methane (CH4) and hydrogen sulphide (H2S). 

Even though the volume of the solid material being deposited is reduced continuously 

by anaerobic decomposition, there is always a net accumulation of 

sludge in the tank. Materials from the bottom of the tank, which is buoyed up 

by the decomposition gases, will often stick to the bottom of the scum layer and 

increase its thickness. The long-term accumulation of scum and sludge can reduce 

the effective volumetric capacity of the tanks. Therefore, in order to function 

the tanks must be desludged regularly (according to Danish experience at 

least once a year). 

There are basically three types of septic tank i.e. tanks with one-, two- or three 

chambers. The function of the compartments is basically to limit the discharge 

of solids in the effluent from the septic tank. According to the Sg. Bintangor 

study, the most common type used in the Sg. Bintangor catchment area is a 

conventional two-compartment tank of a standard size of 2.3-2.6 m 3 . 

Septic tanks are not very efficient. According to Danish experience (Danish 

EPA pers comm., 2000), only about 30 % of the organic matter are removed 

prior to discharge, even in the most efficient three-chambered type with a capacity 

of at least 2 m 3 . Tanks with less number of chambers and in smaller capacity 

are apparently less efficient. In addition, nutrients are basically not all 

removed in septic tanks. As much as 72% and 76 % of the total discharge of 

Phosphorous and Nitrogen, from households are from blackwater (SUD-02-13). 

Consequently, even an optimal functional septic tank in Kuching is a one of th 

esignificant sources of organic matter and nutrients. 

The Rule of “Compulsory desludging of septic tanks, 1988” gazetted 15 th October 

1998 specifies that every septic tank in the city must be desludged every 

second year. The Sg. Bintangor study showed that this rule is not complied 

with. It was estimated that only 840 septic tanks of around 3,000 in the Sg. Bintangor 

catchment area was desludged in a two year period i.e. only about 30% 

of those which should have been desludged according to the rule. Presently, 

tanks are only pumped out at the request of the owner when there is a problem 

or blockage of the system. 


87


On 1 st January 2000, DBKU launched a programme in which the two-year 

desludging period for septic tanks must be applied. The two subcontractors 

ENV and TRAMAS carry out the desludging for DBKU and the sludge is 

treated at the Matang Septic Sludge Treatment Plant. It may, however, be very 

difficult to achieve the intention of programme. According to the Sg. Bintangor 

study (SUD-02-09), more than 95 % of the septic tanks were in fact not accessible 

and many people did not even know whether they had septic tanks or not. 

As a consequence of the improper function of septic tanks, blackwater is discharged 

more or less untreated to the drainage system in Kuching. Untreated 

blackwater from households is undoubtedly the main source of the extremely 

high levels of faecal coliforms in the tributaries and Sg. Sarawak Proper as well 

as a major source contributing the organic matter and nutrients. 

It must be stressed that even if all septic tanks in Kuching were desludged regularly 

and functioning properly, the effect of reducing the load to the tribuatries 

and Sg. Sarawak Proper will be insignificant. Rough estimates of the discharge 

of BOD, Nitrogen and Phosphorous to Sg. Sarwak in the case of all septic tanks 

are not functioning and in case of all septic tanks are functioning optimally are 

presented in Fig. 61. The discharge of BOD will still be very high and the discharge 

of nitrogen and phosphorous are not reduced at all. 

kg/day 

5000 

4500 

4000 

3500 

3000 

2500 

2000 

1500 

1000 

500 

0 

BOD Nitrogen Phosphorous 

None functioning All functioning 

Figure 6.1. Estimated discharge to Sg. Sarawak of BOD, Nitrogen and Phosphorous 

in blackwater in case none of the septic tanks are functioning and in 

case all are functioning optimally. The estimates are based on the population 

size of 215,000 in the sub-catchment areas discharging to Sg. Sarawak and a 

generation of 20g BOD/person/day, 11g Nitrogen/person/day and 1,6 g Phosphorous/person/day 

and an efficiency of 30% removal of BOD in a functioning 

septic tank) 

There are some central treatment-facilities (mostly septic tanks and Imhoff 

tanks) servicing larger housing schemes. The locations of these are presented in 

Fig. 6.2. 


88


6.2.4 Control and Enforcement Measures 

Presently, there are no active control and enforcement measures implemented 

for household discharge in Kuching. As mentioned above, septic tanks are 

pumped out at the request of the owners. However, there is no control on 

whether the tanks comply with the stipulated water quality standards or whether 

the two-year desludging period is complied with especially when the public 

awareness regarding septic tanks is quite low. 

6.2.5 Estimated Ttotal Load of Pollutants from Households 

The total load of different pollutants from households in the twelve subcatchment 

areas have been estimated based on the results of measurements on 

greywater from the households and the numbers of different households. Alternative 

estimates based on population size and estimated loads per person from 

the measurements in Kuching and European values were also elaborated. Estimated 

load from blackwater was based on European values. It was assumed 

that the blackwater is discharged untreatedly. Details are presented in Volume 2 

of the River Quality Baseline Study Report. The main findings are presented 

below. 

None of the households visited in the SUD study complied with the standards 

as stipulated in the Environmental Quality (Sewage and Industrial Effluents) 

Regulations, 1979. The levels in the outlets generally exceeded the standard A 

2-17 times for BOD, 1.1-11 times for COD and 1.5 times for TSS (Cf. Table 

6.3). Non-compliance with the standards is most likely the case for the bulk of 

the houses in Kuching as the sewage is not treated before discharge. 


89


Table 6.3 Households. Results analysis of pollutants in greywater. The values 

are compared to the standards as stipulated in the Environmental Quality 

(sewage and industrial effluents) regulations, 1979. Figures in italic bold indicate 

values exceeding the Standard A and figure in bold also exceed the 

Standard B values. 


De- 

tached 

Semi- 

de- 

tached 

Terrace Kam- 

pung 

Squat- 

ter 

Stan- 

dard A 

Stan- 

dard B 

PH 6.6 9.6 6.7 7.9 6.4 6-9 5.5-9 

BOD, mg/l 43.0 159.0 333.0 114.0 47.0 20 50 

COD, mg/l 76.2 400.0 533.0 133.0 57.1 50 100 

TSS, mg/l 30.0 74.0 225.0 101.0 174.0 50 100 

NH 4-N mg/l 0.2 2.7 43.4 80.3 0.3 

Tot-N, mg/l 4.8 17.4 58.5 93.9 2.2 

Tot-P, mg/l 5.6 19.2 56.7 6.4 5.9 

Oil & Grease, mg/l 2.8


Table 6.4 Households. Estimated loads of different pollutants from different 

catchment areas (kg/day) from both grey and blackwater. 

Catchment BOD 

South of Sg. 

Sarawak 

Kg/day 

COD 

Kg/day 


TSS 

Kg/day 

Tot N 

Kg/day 

Tot P 

Kg/day 

Bintangor-1 106-198 349-528 100-167 53-70 9-12 

Bintangor-2 199-299 595-797 178-253 80-105 17-18 

Bintangor-3 126-259 434-690 123-218 68-91 10-16 

Padungan 494-703 1452-1874 439-594 189-249 42 

Sekama 91-158 290-422 85-133 43-56 8-9 

Sekama 1 56-101 181-270 53-86 27-36 5-6 

Periok 20-33 63-89 18-28 9-12 2 

Biawak 71-126 229-337 66-107 34-44 6-8 

Bintawa 32-72 115-192 32-61 18-25 3-4 

Bintawa 1 286-536 942-1428 271-452 144-188 23-32 

Kudei 254-367 747-978 225-310 99-129 21-22 

Maong 2646-4239 8131-11303 2407-3579 1140-1488 219-254 

North of Sg. 

Sarawak 

Gita 216-402 709-.072 204-340 108-141 18-23 

Laruh 171-269 521-717 155-227 72-94 14-16 

Turong 40-61 120-163 36-52 16-21 3-4 

Sinjan 288-478 898-1.274 264-403 128-168 24-29 

Bedil 232-413 747-1.100 217-348 111-145 19-25 

Gersik 66-113 208-300 61-95 30-40 5-7 

Seman Lama 335-517 1.013-1.378 302-437 139-181 28-31 

Siol Kandis 1 179-337 591-899 170-285 91-118 15-20 

Siol Kandis 2 16-25 49-67 15-21 7-9 1-2 

Total 5925-9705 19927-25880 5421-8195 2610-3407 490-582 

6.3 Pollution from Food Outlets 

6.3.1 Types of Food Outlets and Types of Pollutants 

Food outlets comprise: 

Food centres with several different stalls serving food; 

Individual restaurants, coffee shops and fast food restaurants; and 

Markets. 

The most significant pollutants in wastewater, which have been chosen as indicators 

from food outlets are ammoniacal nitrogen, phosphorous, BOD, COD, 

TSS and Oil & Grease. 

91


6.3.2 Estimated Number of Different Food outlets 

The SUD Project has estimated the number of different types of food outlets in 

the twelve catchment areas, which are discharging to Sg. Sarawak upstream of 

the barrage. The result is summarised in Table 6.5. The food centres and individual 

restaurants are mainly located at the south of Sg. Sarawak, mainly at the 

Sg. Maong and Sg. Padungan sub-catchment areas (Table 6.5). Large markets 

with more than 100 stalls are located in Bintangor 2, Bintangor 3, Padugan and 

Maong. 

Table 6.5 Number of different types of Food-outlets in different Subcatchment 

areas. Locations of the sub-catchment areas are indicated on Fig 

4.3 in section 4.1 

Catchment Food Center Individual 

South of Sg. 

Sarawak 

Restaurants, 

Coffee Shops 

and Fast Food 

Restaurants 

Big Markets 

(more than 

100 stalls) 


Medium 

Markets (Be- 

tween 50 and 

100 stalls) 

Small Mar- 

kets 

(Less than 50 

Bintangor 1 - - - - - 

Bintangor 2 1 48 2 1 - 

Bintangor 3 2 88 1 2 - 

Padugan 2 108 2 - - 

Sekama - 73 - - - 

Sekama 1 - 6 - - - 

Periok - 16 - - - 

Biawak 1 22 - 1 - 

Bintawa - 8 - - - 

Bintawa 1 - - - - 1 

Kudei 1 8 - - 1 

Maong 1 131 1 - - 

North of Sg. 

Sarawak 

Gita 1 - - - - 

Laruh 1 - - - - 

Turong - - - - - 

Sinjan - 4 - - 1 

Bedil - - - - - 

Gersik - - - - - 

Seman Lama - - - - - 

Siol Kandis 1 - - - - - 

Siol Kandis 2 - - - - - 

Total 10 512 6 4 3 

stalls) 

92



The food outlets discharge wastewater to the open drains in the city. Most food 

outlets discharge untreated water while have equipped with some form of 

treatment facilities. The treated water from such facilities is also discharged to 

the drain. Treatment facilities include: 

Crude devices in the form of steel basins, which serves to trap oil and 

grease and collect solid food residues washed down from the kitchen sinks 

in restaurants; 

Filtration systems consisting of “sponge-like” filter material installed at the 

bottom of the washing sink of restaurants to trap large solid food residues 

washed into the sink‟s piping system; and 

Grease traps installed at the outlet to the peripheral drains. 

The Sg. Bintangor study (SUD-02-09) indicated that the grease traps are generally 

not functioning because they were not emptied and in the case they are actually 

emptied, it seemed that this generally took place in the drain downstream 

of the trap. 

At present, information on numbers of food outlets with treatment facilities is 

not available. 


Presently, the Local Councils spend huge resources in cleaning the oil and 

grease in the drains downstream of food outlets. 

6.3.5 Estimated Total Load of Pollutants from Food Outlets 

The total load of different pollutants from different types of food outlets in the 

twelve sub-catchment areas have been estimated based on the results of measurements 

on wastewater from different types of outlets and the estimated number 

of different types of food outlet. Details are presented in Volume 2 of the 

River Quality Baseline Study Report. The main findings are presented below. 

The greywater from the food outlets investigated in this study does not comply 

with the standards as stipulated in the Environmental Quality (Sewage and Industrial 

Effluents) Regulation, 1979 (Table 6.6). The levels in the outlets generally 

exceed the Standard A: 

13-42 times for BOD; 

2-21 times for COD; and 

2-7 times for TSS. 


93


Compliance for the food centre, coffee shop and market could not be expected, 

as the water is not treated in any way before discharge. The restaurant has a collection 

basin after outlet from kitchen sink and the fast food restaurant has a 

filtration system after the outlet from kitchen sink. These systems are not sufficient 

for a proper wastewater treatment. 

Table 6.6 Food outlets. Results of pollutants in wastewater. The values are 

compared to the standards as stipulated in the Environmental Quality (sewage 

and industrial effluents) regulations, 1979. Figures in italic bold indicate 

values exceeding the Standard A and figure in bold also exceed the Standard 

B values. 

Food 

Centre 

Restau- 


rant 

Coffee 

Shop 

Fast- 

food 

Market Stan- 

dard A 

Stan- 

dard B 

PH 6.8 6.2 8.0 7.9 6.0 6-9 5.5-9 

BOD, mg/l 660 833 278 390 260 20 50 

COD, mg/l 676 1,040 405 624 295 50 100 

TSS, mg/l 372.0 268.0 90.7 220.0 110.0 50 100 

NH 4-N, mg/l 0.26 67.10 0.15 0.13 12.6 

Tot-N, mg/l 8.34 0.43 1.84 16 26.5 

Tot-P, mg/l 8.72 2.68 3.62 1.73 9.22 

O&G, mg/l 124.0 2.14 12.0 155.0 17.8 n.d 10 

The estimates of the discharge of pollutants are presented in Table 6.7. The 

highest pollution load is discharged from the Padungan sub-catchment area followed 

by Maong, Bintangor 3 and Bintangors. 

94


Table 6.7 Food-outlets. Estimated loads of different pollutants from food outlets 

in the different catchment areas (kg/day). 

Catchment BOD COD 

South of Sg. 

Sarawak 


TSS 

Tot N 

Bintangor-1 0 0 0 0 0 

Bintangor-2 122.4 146 50 9 3 

Bintangor-3 124 156 50 7 3 

Padungan 153 192 62 8 3 

Sekama 51 71 20 1 0 

Sekama 1 4 6 2 0 0 

Periok 11 16 4 0 0 

Biawak 28.4 35 11 1 1 

Bintawa 6 8 2 0 0 

Bintawa 1 4 4 2 0 0 

Kudei 10 13 4 0 0 

Maong 131 171 52 5 2 

North of Sg. 

Sarawak 

Gita 0.4 0 0 0 0 

Laruh 0.4 0 0 0 0 

Turong 0 0 0 0 0 

Sinjan 7 8 3 0 0 

Bedil 0 0 0 0 0 

Gersik 0 0 0 0 0 

Seman Lama 0 0 0 0 0 

Siol Kandis 1 0 0 0 0 0 


Total 651.4 827 263 33 12 

6.4 Pollution from Industries 

6.4.1 Types of Industries and Types of Pollutants 

There are three main industrial estates in Kuching: 

Tot P 

Pending Industrial Estate. This estate comprises industries of food processing, 

wood ,wood/cork processing, furniture manufacturing, chemical 

products and plastic product processing; 

Demak Laut Industrial Park at the north of the Barrage. This estate comprises 

industries of wood and wood/cork processing, furniture manufacturing 

and food processing; 

Sama Jaya Free Industrial Zone. This estate is dominated by electronics 

industries. 

95


In addition to the large industrial estates, small workshops (such as automobile 

and garage shops) are distributed all over the city especially to the south of Sg. 

Sarawak (Cf. Section 6.4.5, Table 6.10). 

The industries generate a wide variety of pollutants. Table 6.8 provides an 

overview of typical pollutants from different types of industries. 

Table 6.8 Overview of types of wastewater pollutants produced by different 

types of industries in Kuching. 

Point Sources Type Pollutants Indicators 

Workshops 

Printing 

Food Processing 

Rubber Processing 

Metal Industry 

Electronics / 

Semi-Conductors 

Industry 

Ceramic process- 

ing 

Glue Manufactur- 

ing 

Batteries Manu- 

facturing 

Paint Industry 

Repair Shops, Ga- 

rages 

Paper mill, News- 

Oil and Grease, Spent 

Solvents, etc 


print 

Noodles, Biscuit, 

Seafood, Poultry, 

Soy Sauce, Canning, 

Beverages, etc 

Smoked Rubber 

Sheet 

Spent solvents, wasted 

ink 

Wash water, Effluent 

wastewater 

pH, Oil and Grease, TSS, 

Colour 

Colour, COD, TSS, Chlo- 

rine, Chromium, Barium, 

Silver 

pH, Oil & Grease, COD, 

BOD, TSS, Nitrogen, 

Phosphorus, Colour. 

Effluent Wastewater pH, TSS, BOD, COD, 

Steel Manufacturing Spent acid, spent sludge, 

Aluminium Extru- 

sion 

Galvanising (Zinc & 

Nickel) 

Microchips, Printed 

Circuit Board, etc 

Floor Tile, Wall 

Tile, Sanitary Fix- 

tures 

Adhesives for ply- 

wood 

Assembly of batter- 

ies 

Water-base Paint, 

Solvent Paint 

rinse water 

Spent Solvent, spent 

acid, wash water 

Wash water, effluent 

wastewater 

Nitrogen 

pH, COD, TSS, Oil and 

Grease, Lead, Arsenic, 

Zinc, Iron, Chromium, 

Aluminium, Manganese 

pH, COD, TSS, Nickel, 

Chromium III and V, Tin, 

Lead, Aluminium, Sul- 

phate 

pH, COD, TSS, Nickel, 

96 

Chromium III and V, Iron, 

Lead, Zinc 

pH, COD, TSS, Lead, 

Tin, Nickel, Copper, Zinc, 

Cadmium, Selenium, 

Arsenic, AOX. 

TSS, Colour, COD, Iron, 

Lead, Zinc, Cadmium 

Wash water, spillage pH, phenol, formalde- 

Spent acid, spent 

sludge/slurry 

Spent Solvent, Spent 

Sludge, Rinse Water 

hyde, urea, methanol 

pH, TSS, COD, Lead, 

Sulphate 

pH, COD, TSS, Oil and 

Grease, Lead, Nickel, 

Copper, Zinc, Cadmium.


6.4.2 Estimated Number of Different Types of Industries 

The SUD Project has estimated the number of different types of industries in 

the twelve catchment areas, which are discharging to Sg. Sarawak upstream of 

the barrage. This area includes only the industrial estate at Pending. The industrial 

estates: Demak Laut Industrial Park and Semajaya Free Industrial Zone are 

not included. 

The results of the estimate are summarised in Table 6.9. The industries are 

clearly concentrated in the Pending area (i.e. sub-catchment areas: Sekama 1, 

Periok, Biawak, Bintawa, Bintawa 1). Most of the industries in the Pending 

area are SMIs, which are engaged in food processing (baking, canning, beverage 

production, preserving of fish and crustacean); wood processing, printing 

and metal works (aluminium extrusion, steel manufacturing and galvanising). 

Table 6.9 Number of different types of Industries in different Sub-catchment 

areas 

Catchment Printing Food proc- 

South of Sg. 

Sarawak 

essing 

Rubber 

processing 


Alumi- 

nium 

Steel Galvanis- 




Padugan 2 - - - - 

Sekama - - - - - 

Sekama 1 1 2 1 - - 

Periok 1 5 1 - - 

Biawak 4 17 13 2 6 1 

Bintawa 5 2 - 2 2 - 

Bintawa 1 3 61 3 2 5 3 

Kudei - - - - - - 

Maong - 6 - - 5 2 

North of Sg. 

Sarawak 

Gita - - - - - - 

Laruh - - - - - - 

Turong - - - - - - 

Sinjan - - - - - - 

Bedil - - - - - - 

Gersik - - - - - - 

Seman Lama - - - - - - 

Siol Kandis 1 - - - - - - 

Siol Kandis 2 - - - - - - 

Total 16 93 18 6 18 6 

ing 

97


Table 6.10 Number of different types of Industries in different Subcatchment 

areas. 

Catchment Wood 

process- 


ing 

Ceramic 

process- 

ing 

Batteries 

manu- 

facturing 

Paper 

Mills 

Work- 

shops 

Petrol 

stations 

Bintangor 1 - - - - 2 1 3 

Bintangor 2 - - - - 28 - 34 

Bintangor 3 - - - - 23 - 24 

Padugan 12 - - - 131 9 31 

Sekama 1 - - - 113 1 1 

Sekama 1 3 - - - 2 - 2 

Periok 12 - - - 47 1 2 

Biawak 8 2 2 1 22 - 2 

Bintawa 10 - - - - - 3 

Bintawa 1 49 - 2 - 11 - 7 

Kudei 2 - - - 2 - 2 

Maong 38 4 - - 135 14 53 

Gita - - - - 3 1 4 

Laruh - - - - 17 3 3 

Turong - - - - 3 - - 

Sinjan - - - - 2 1 8 

Bedil - - - - - - 5 

Gersik - - - - - - 3 

Seman Lama - - - - - - 2 

Siol Kandis 1 - - - - - - 1 

Siol Kandis 2 - - - - - - - 

Others 

Total 135 6 4 1 551 31 521 


Many Industries would have a wastewater treatment system in place. However, 

there are quite a few industries without any or insignificant wastewater treatment. 

Presently, data on number of industries with a proper wastewater treatment 

system and number of industries without is not available. An overview of 

treatment facilities at the industries visited during the SUD field study is presented 

in the Volume 2 of the River Quality Baseline Study Report. 


Currently, the enforcement with regards to compliance to the Environmental 

Quality Act 1974 (EQA) Standards is carried out by the Department of Environment 

(DOE) who conducts regular sample collection and analysis of the following 

industries: 

Industries discharging more than 60 m 3 wastewater per day or where the 

total load of BOD in effluents exceed 6 kg per day; 

98


Industries involved in processing of oil palm fruit; and 

Industries involved in the processing of rubber. 

The industries regulated by DOE only constitute a minor fraction of the total 

number of industries situated in Kuching. 

6.4.5 Estimated Total Load of Pollutants from Industries 

The total load of different pollutants from different types of industries in the 

twelve sub-catchment areas have been estimated based on results of the measurements 

on wastewater from different types of outlets and the estimated number 

of different types of industries. Details are presented in Volume 2 of the 

River Quality Baseline Study Report. The main findings are presented below. 

It was found that the wastewater from the industries with treatment facilities 

generally complies with the standards as stipulated in the Environmental Quality 

Regulation. This clearly showed at the visited cases for steel-, aluminium-, 

galvanising-, rubber-, beverage- and seafood- industries as well as the slaughterhouse. 

On the other hand, the wastewaters from the industries without treatment 

systems significantly violate the standards especially for the parameters of 

BOD, COD TSS, Oil & Grease. This is conformed to the case for the ceramic-, 

the paint- and the printing industries. 

The highest load is of pollutants from industries is unsurprisingly from the 

catchment areas in Pending (Sekama1, Periok, Biawak, Bintawa, Bintawa 1) 

followed by Padungan and Maong (Table 6.11). 


99


Table 6.11 Industries. Estimated loads of different pollutants from industries 

in the different catchment areas (kg/day). 

Catchment BOD COD 

South of Sg. Sara- 

wak 


TSS 

Tot N 



Bintangor-3 0 0 0 0 

Tot P 

Padungan 0.14 0.23 0.061 0.021 0.0084 

Sekama 0 0 0 0 0 

Sekama 1 0.26 0.74 0.53 0.12 0.0676 

Periok 0.43 1.26 0.79 0.25 0.1606 

Biawak 3.76 10.39 18.60 1.18 0.628 

Bintawa 1.61 6.63 8.33 0.21 0.099 

Bintawa 1 4.12 13.67 7.44 3.11 2.018 

Kudei 0 0 0 0 0,00000 

Maong 3.30 6.92 24.99 0.45 0.303 


wak 

Gita 0 0 0 0 0 

Laruh 0 0 0 0 0 

Turong 0 0 0 0 0 

Sinjan 0 0 0 0 0 

Bedil 0 0 0 0 0 

Gersik 0 0 0 0 0 

Seman Lama 0 0 0 0 0 



Total 13.62 39.85 60.75 5.33 3.285 

6.5 Pollution from Agriculture 

6.5.1 Types of Agricultural Activity and Types of Pollutants 

One of the main sources of pollution from agriculture is from livestock farming, 

particularly from pig farms. 

Based on the list from the NREB Livestock Unit, there are currently fifty-nine 

pig farms within the Kuching, Serian, Bau and Samarahan regions. The standing 

pig population is about 61,000. 

Pollutants, which have been chosen for indicators for pig farms, include BOD, 

COD, TSS, Tot-N, Amm-N, Phosphorus, Faecal Coliforms and Total Coliforms. 

100


Other sources of pollution from agriculture include oil palm plantations and 

horticulture farms upstream of Kuching. Pollutants from these include nutrients 

(fertilisers) and pesticides. At present, there is no available information on the 

amount of agrochemicals used or discharged. 


The wastewater from most pig farms in the Kuching area is treated in a two- 

pond system, in which organic matter is digested by anaerobic bacteria in one 

pond and by aerobic bacteria in the other. These ponds are normally constructed 

from earth and are generally rectangular in shape, with dimensions of 

typically about 10m x 12m each for a farm with a standing pig population 

(SPP) of about 1,000-2,000. 

Farmers who do not have sufficient space for the two-pond system use other 

treatment methods. Among the ones more commonly used are the solid-liquid 

slurry separator machines which separates the solids from the liquids of the 

wastewater from the pig farms. This technology is not very efficient in degrading 

organic matter. 

None of the systems are very efficient. One major problem being that is the 

sludge ultimately ends up in the river. 


Currently the enforcement with regards to compliance to the Natural Resources 

and Environment (Control of Livestock Pollution) Rules, 1996 is carried out by 

the Natural Resources and Environment Board (NREB). NREB receives two 

reports from licensed pig farms each year. The concentrations of BOD, COD 

and TSS in the discharge must be reported and certain limits in three successive 

phases must be complied with (Cf. Table 6.12). In addition, NREB carries out 

their own sampling and analysis of water from the ponds at licensed and unlicensed 

pig farms. 

Table 6.12 Water quality standards for wastewater from pig farms 

Permitted concentration in discharge from 

existing farms 

Phase 1 Phase 2 Phase 3 

BOD, mg/l 1.300 250 50 

COD, mg/l 2.500 1.000 500 

TSS, mg/l 1.500 300 100 

Permitted concentration in discharge from 

new farms: 

Phase 1 Phase 2 Phase 3 

BOD, mg/l 500 250 50 

COD, mg/l 2.500 1.000 500 

TSS, mg/l 1.500 300 100 


101


6.5.4 Pollutant Concentration in Wastewater from Pig Farms 

Table 6.13 shows the results of NREB analysis of pond water from different pig 

farms in the Kuching area. In most cases, the pig farms recorded marginally 

comply with the Phase 3 discharge limit posed by the legislation (Cf. Table 

6.12 and Table 6.13). Most of the farms however, comply with the Phase 2 discharge 

limits. 

Table 6.13 Results of NREB measurements of concentrations of BOD, COD 

and TSS in water collected from wastewater ponds at pig farms upstream of 

Kuching. 

Standing Pig 

Population 

BOD (mg/l) COD (mg/l) TSS (mg/l) 

1 89 69 69 123 

2 80 0 0 0 

3 2000 515 3400 500 

4 200 45 164 55 

5 1600 40 132 38 

6 200 17 82 60 

7 300 219 952 760 

8 500 23 126 100 

9 305 47 246 75 

10 1220 59 278 135 

11 150 10 10 10 

12 800 169 636 300 

13 150 23 74 230 

14 1800 25 58 170 

15 300 0 0 0 

16 5000 120 354 158 

17 1200 0 0 0 

18 2000 31 60 180 

19 200 117 224 130 

20 1200 97 462 160 

21 3200 137 434 105 

22 2000 90 528 170 

23 1500 30 108 65 

24 3000 0 0 0 

25 300 137 348 293 

26 1100 11 58 320 

27 500 51 60 45 

28 1500 143 510 215 

29 1500 51 278 105 

30 na na na na 

31 500 117 224 130 

32 800 49 208 100 

333 700 51 186 55 

34 1200 33 74 590 

35 300 25 70 40 

36 280 39 222 120 


102


Table 6.13 continued 

Standing Pig 

Population 

BOD (mg/l) COD (mg/l) TSS (mg/l) 

37 180 99 300 140 

38 2500 105 264 118 

39 150 35 202 80 

40 350 507 1198 530 

41 500 67 252 1350 

42 3500 50 152 235 

43 1000 16 72 21 

44 1500 67 316 77 

45 2500 75 126 75 

46 1500 100 338 235 

47 60 na na na 

48 1500 16 84 98 

49 300 59 124 86 

50 800 219 952 760 

51 800 168 374 165 

52 800 89 302 210 

53 500 62 274 85 

54 300 18 174 12 

55 1800 20 74 70 

56 2500 26 214 95 

There is no information on flow of wastewater from the pig farms. Therefore, it 

is not possible to estimate the total load from the farms as for households, food 

outlets and industries. 

According to the NREB records, the standing pig population in the Kuching 

area is about 61,000. According to Danish experience, one pig produces as 

much as 200g BOD/day. This is 3-4 times more than the amount produced by 

humans. The total amount of BOD produced by pigs in the Kuching area can 

thus be estimated at some 12,000 kg BOD/day, which is of the same magnitude 

as the amount of BOD estimated to be discharged from households in Kuching 

(exclusive of the households in the Sg. Kuap catchment). Some reduction of 

BOD levels takes place in the treatment ponds, consequently, the amount of 

organic pollutants discharged to the river would be smaller than the 12,000 kg 

BOD/day. However, it would seem that pig farms are the significant source of 

pollution of organic and faecal bacteria to the river system. 

6.6 Other Sources of Pollution 

Other sources of pollution to the river include: Hospitals and clinics, shopping 

centres, large commercial buildings, river vessels, port, dockyards and ship repair 

areas along Sg. Sarawak. These sources are less importance compared to 

those described above. 


103


Hospitals and clinics 

Hospitals and clinics generally have their own sewage treatment systems. 

Clinical waste (infectious refuse, bodily parts and organs, blood supplies, transfusion 

bags, disposable syringes, expired medicines, used chemicals, bandaging 

materials, etc) is incinerated and is not discharged to the river. 

Shopping centres, large commercial buildings and hotels 

Large establishments such as shopping centres, which mainly comprise various 

types of commercial businesses ranging from textile vendors, hairdresing saloons, 

electronics shops produced varied liquid waste. Other than sewage from 

the septic tanks, other types of waste which are water-based include chemicals 

used in cleaning floors and windows, used aerosol cans, fluorescent tubes and 

other mercury-containing waste, used batteries, solvents, ink residues, dyes, etc. 

Most hotels have their own treatment systems. Many commercial buildings that 

have their own treatment facilities (mostly septic tanks) are often inducing considerable 

pollution problems locally, and often give rise to complaints from 

neighbours due to the odour. The septic tanks are not regularly maintained and 

as mentioned above, septic tanks are not very efficient even when they function 

properly. 

River vessels, port, dockyards and ship repair areas 

Liquid waste from river vessels mainly oil and grease-based and is mostly produced 

onboard during machinery or engine servicing/maintenance works and 

fuel refilling at the docks. Unused fuels are kept in metal drums and stored on 

board the ships (for those with the capacity to do so) or at the docks. It is assumed 

that used fuel is discarded off the vessels into drums and stored at the 

docks or storage areas. Paint substances would be related to repair works conducted 

at the dry docks. 

Mining areas 

Within the Kuching region, the main mining activities are associated with limestone 

and sand mining (for the cement and construction industry) and loam/clay 

mining for brick-production industry. These areas are located mostly south and 

south-west of the city towards Bau-Serian areas. In Bau, there are abandoned 

gold mines and presently no active ones. There is presently no record of any 

mining waste within Kuching City. From the limestone and loam/clay mining 

activity, the types of waste generated would mainly be solid waste in the form 

of fine dust and debris, soil erosion effects and sedimentation into waterways 

and nearby streams/rivers. There are indications that sediments polluted by 

heavy metals in the gold mining areas in the past that may be transported downstream 

of the river (Cf. Section 5.3) 


104


INSERT NEW MAP FROM DAYA RANCANG 

Fig 6.2. Location of housing schemes connected to centralised treatment systems and commercial buildings, government buildings, hospitals, hotels 

etc, with own treatment systems. 


105


6.7 Other Sources of River Quality Deterioration 

In addition to the discharge of pollutants, the spillage and discharge of soil due 

to logging, dredging and transportation of sand by barges and construction of 

roads and highways and landclearing for plantation and urban projects are potentially 

affect the river quality. In addition, the presence of the barrage may 

have a deleterious impact on the river quality. 

Logging activity 

Most logging activities operated upstream are located far from the Sg. Sarawak 

catchment, therefore, impacts from such activity is minimal, if any. There may 

be logging activities at the areas bordering Kalimantan, however at this stage, 

there is no record available. For the State of Sarawak, the most affected river 

systems are those located towards the north and north-east, i.e. Batang Rajang 

in Sibu and Sg. Baram in Miri. Logging activities would generally impact river 

water quality in terms of the accumulation of runoff from soil erosion forming 

sediments, which flow into the streams, rivers and existing waterways. 

Transportation of extracted sand by barges downstream 

Extraction of sand from the riverbed and transportation of the sand is one of the 

potential contributers to increase in sedimentation levels in the river. This is 

mainly due to small spillage, which occurs during extraction from the river bottom 

and during travelling from the extraction point to the final destination, located 

further downstream and/or outside of the barrage area. Wind-blown sand 

for instance from the uncovered top of the sand-carrying barrage would settle 

onto the river banks and river bed at any location along the river during the occurrence 

of strong winds and in time, the cumulative effect would be such that 

sediment levels will rise at these locations. 

Construction of roads, clearing for plantations and urban development 

Construction of roads, clearing for plantations and urban development located 

along tributaries of Sg. Sarawak or along Sg. Sarawak itself has the potential 

contributing sedimentation of soil runoff due to surface erosion from rainfall 

effects. The construction of the Borneo Heights Road Project, for example, 

which approximately 25 km and located close to the upstream tributaries of Sg. 

Sarawak Kiri (Sg. Abang, Sg. Semadang and Sg. Temurang), would have also 

contributed to the potential increase in sedimentation in the streams and eventually 

in the river. Runoff from the construction areas reaches the tributary 

streams via a network of roadside and cascading drain system installed for the 

road project. Another recent project is work-in-progress of the road built almost 

parallel to the Sg. Sarawak northern bank, i.e. Petra Jaya region. The construction 

of this road would presumably has some impacts on the sedimentation levels 

of the river, particularly in relation to surface runoffs during rainfall. 

Effect of the Barrage 

Kuching Barrage Management is currently operating a flushing scheme to mitigate 

environmental impacts of the barrage. Potential impacts, which are miti- 


106


gated by the flushing scheme, are discussed in various previous sections. They 

are: 

Reduction of saltwater intrusion and river flow velocity; 

Increase of sedimentation of suspended matter due to reduction of flow velocities 

Increased risk of oxygen depletion and accumulation of organic material, 

nutrients and bacteria upstream of the barrage; 

Risk of impacts on mangroves and nipah forests due to the decreased salinity; 

Risk of reduction of the stock of the giant freshwater prawn which is an 

important commercial species, due to blocking of migration routes to and 

from spawning and nursery grounds downstream of the barrage; and 

Reduction of the population and catch of marine and brackish water species 

fish in the river due to reduced salinity. 

Should the flushing scheme for some reason be inadequate in the future, there 

is a risk that measures to improve the water quality may be affected by the 

presence of the barrage. The interpretations of state indicators in the EMS 

should therefore always be related to the operation of the barrage. 


107


7 Discussion and Conclusion 

7.1 Degree of Pollution 

The baseline study has documented that the tributaries of Sg. Sarawak situated 

in Kuching City and Sg. Sarawak fronting Kuching are significantly polluted. 

The major problems are serious pollution with faecal-derived coliform bacteria 

and pollution with organic matter, leading to oxygen deficiency, deleterious 

impact on bottom fauna and offensive odour. The source of the pollution is untreated 

and insufficiently treated sewage and wastewater, which is discharged 

directly to the open drains in the city. 

The water qualities of different zones of the entire river system have been classified 

according to the Malaysian Interim National Quality Standards 

(INQWS). A summary of the results of classification is presented below. 

The water qualities in the tributaries Sg. Maong, Sg. Bintangor, Sg. Padungan 

Sg.Sekama and Sg. Tabuan in the city are very poor and fall between 

class IV and class V of the INWQS standards. 

The water quality in the stretch of the main Sg. Sarawak Proper. The water 

can be classified as class III in terms of physico-chemical parameters. 

However, in terms of bacteriological parameters, the water is only class V. 

The water quality in Sg. Sarawak upstream of Kuching, including Sg. Sarawak 

Kiri and Kanan is quite good and generally complies with class 

IIA/IIB in terms of physico-chemical parameters. However, the water does 

not meet the class IIB standards for faecal-derived bacteria. 

7.2 Sources 

From the results of the pollutant load estimation exercise carried out for household, 

food outlets and industry in the previous section, a comparison of their 

combined yearly loading were made to assess their respective contribution to 

the pollutant load of Sg. Sarawak and tributaries. 

Table 7.1 presents an overview of the estimated total loads of pollutants to Sg. 

Sarawak and tributaries from households, food outlets, industries and others. 


108


Untreated sewage from households is identified as the most significant source 

of pollution as a whole. The loads of BOD, COD, TSS, Tot-N, Tot-P and oil 

and grease from households are orders of magnitude larger than the loads from 

food outlets (markets, food centres, restaurants etc.), industries and other 

sources. 

Food outlets (restaurants, markets etc.) are, however, the significant local 

source of pollution in the central business centre immediately south of Sg. Sarawak. 

In sub-catchment areas Bintangor 2, Bintangor 3, Padungan, Periok and 

Biawak, 20-40% of the BOD load and as much as 71-83% of the load of oil and 

grease are discharged from food outlets. In Sekama and Bintawa, 83 and 71% 

of the oil and grease are from food outlets (Table 7.3, 7.4 and Fig. 7.1). 

Presently, the Local Councils spend huge resources in these areas cleaning the 

oil and grease in the drains downstream of food outlets due to inadequate 

treatment facilities at the food outlets. 


different types of sources in Kuching. (Rounded figures) 

Households Food outlets 

(Markets, Food cen- 

tres, Restaurants etc) 


Industries 

BOD kg/day 5900-9700 650 15 

COD kg/day 19900-26000 800 40 

TSS kg/day 5400-8000 260 60 

Tot-N kg/day 2600-3400 30 5 

Tot-P kg/day 500-600 10 3 

Oil & grease kg/day 200-350 60 2 

Pb kg/day - - 0.02 

Cd kg/day - - 0.002 

Cu kg/day - - 0.01 

Zn kg/day - - 0.7 

Fe kg/day - - 0.9 

Mn kg/day - - 0.07 

Al kg/day - - 0.9 

AOX kg/day - - 0.009 

109


Table 7 2 Percentage of total load of BOD from households, food outlets and 

industries in each of the 21 sub-catchment areas discharging to Sg. Sarawak.The 

shadings indicate areas where food outlets are contributing significantly 

to the total load. 

Catchment Households 


wak 


% of 

total load from the 

three types of sources 

in the sub-catchment 

area 

Food outlets 

% of 




area 

Industries 

% of 


110 



Bintangor-1 100 0 0 



Padungan 79 20 1 

Sekama 100 0 0 

Sekama 1 98 0 1 

Periok 69 28 3 

Biawak 75 21 4 

Bintawa 89 9 2 

Bintawa 1 97 1 2 

Kudei 97 3 0 

Maong 96 3 1 

North of Sg. Sara- 

wak 

Gita 100 0 0 

Laruh 100 0 0 

Turong 100 0 0 

Sinjan 98 2 0 

Bedil 100 0 0 

Gersik 100 0 0 

Seman Lama 100 0 0 

Siol Kandis 1 100 0 0 


area


Table 7.3 Percentage of total load .Oil and grease from households, food outlets 

and industries in each of the 21 sub-catchment areas discharging to Sg. 

Sarawak.The shadings indicate areas where food outlets are contributing 

significantly to the total load. 

Catchment Households 


wak 


% of 




area 

Food outlets 

% of 




area 

Industries 

% of 


111 






Padungan 29 71 0 

Sekama 17 83 0 

Sekama 1 56 44 0 

Periok 20 80 0 

Biawak 21 79 0 

Bintawa 30 70 0 

Bintawa 1 87 13 0 

Kudei 76 24 0 

Maong 70 30 0 

North of Sg. Sara- 

wak 

Gita 100 0 0 

Laruh 100 0 0 

Turong 100 0 0 

Sinjan 82 18 0 

Bedil 100 0 0 

Gersik 100 0 0 

Seman Lama 100 0 0 



area


Figure 7.1. Areas in Kuching City where more than 70% of the total load of oil 

and grease is discharged from food outlets (in green). 


112


Catchment BOD 

Table 7.4 and 7.5 indicate the total loads of pollutants from the different subcatchment 

areas (sum of load from all sources in each area). 

The load of organic pollution (BOD, COD, TSS, Tot-N, Tot-P and O&G) is the 

highest from the Maong sub-catchment area followed by Padungan, Bintawa1 

and Seman Lama (Table 7.4). 

The highest loads of heavy metals are encountered in the Pending area (Sekama 

1, Periok, Biawak, Bintawa, Bintawa 1), Padungan and Maong. However, it is 

noted that the load estimate only includes loads from industries. There are no 

information of concentrations of heavy metals in outlets from households, foodoutlets, 

workshops and other sources. The load from these sources might actually 

exceed the load from the industries, due to the sheer number of sources. 


different sub-catchment areas in Kuching.(Rounded Figures). The shading 

indicates the four highest loads for each parameter. 

kg/day 

COD 

kg/day 


TSS 

kg/day 

Tot-N 

kg/day 

Tot-P 

kg/day 

Bintangor-1 100-200 350-530 100-170 50-70 9-11 3-7 

O&G 

kg/day 

Bintangor-2 320-420 750-950 230-300 90-120 22-23 19-20 

Bintangor-3 290-420 650-900 170-270 100-120 33-37 13-20 

Padungan 670-880 1700-2100 500-655 200-270 54-55 37-40 

Sekama 150-220 370-500 100-150 45-60 10-12 9-11 

Sekama 1 60-100 190-280 55-90 30-40 5-6 2-4 

Periok 30-40 80-100 20-30 9-12 2 2 

Biawak 100-160 280-390 100-140 40-50 9-11 5-7 

Bintawa 40-80 130-200 40-70 20-30 3-4 1-4 

Bintawa 1 300-540 960-1,400 280-460 150-190 26-33 7-19 

Kudei 270-380 760-1,000 230-315 100-130 23 13-14 

Maong 2,800-4,400 8,300-11,400 2,500-3,600 1,100-1,500 220-250 120-155 

Gita 200-400 700-1,000 200-340 100-140 18-23 5-13 

Laruh 170-270 520-720 155-230 70-95 14-16 7-9 

Turong 40-60 120-160 40-50 15-20 3-4 2 

Sinjan 300-480 900-1,280 270-400 130-170 24-28 11-17 

Bedil 230-400 750-1,100 220-350 110-145 19-24 7-14 

Gersik 70-100 200-300 60-95 30-40 5-7 2-4 

Seman Lama 340-500 1,000-1,380 300-440 140-180 28-30 15-17 

Siol Kandis 1 180-340 590-900 170-290 90-120 15-19 4-11 

Siol Kandis 2 15-25 50-70 15-20 5-10 1 1 

113


Catchment Pb 


different sub-catchment areas in Kuching. 

g/day 

Cd 

g/day 


Cu 

g/day 

Bintangor-1 0 0 0 0 0 0 0 0 

Bintangor-2 0 0 0 0 0 0 0 0 

Bintangor-3 0 0 0 0 0 0 0 0 

Padungan 0 0 0 0.3 2 0.1 2 0 

Sekama 0 0 0 0 0 0 0 0 

Zn 

g/day 

Sekama 1 0.3 0.02 0 1 20 2 10 0.2 

Periok 0.7 0.04 0 2 30 3 1.6 0.2 

Biawak 4.0 0.5 0.2 200 300 20 300 3 

Bintawa 0.4 0.07 0 0 40 3 100 1 

Bintawa 1 10 0.9 0 100 300 30 100 2 

Kudei 0 0 0 0 0 0 0 0 

Maong 2 0.2 0.4 0.4 100 7 400 1 

Gita 0 0 0 0 0 0 0 0 

Laruh 0 0 0 0 0 0 0 0 

Turong 0 0 0 0 0 0 0 0 

Sinjan 0 0 0 0 0 0 0 0 

Bedil 0 0 0 0 0 0 0 0 

Gersik 0 0 0 0 0 0 0 0 

Seman Lama 0 0 0 0 0 0 0 0 

Siol Kandis 1 0 0 0 0 0 0 0 0 

Siol Kandis 2 0 0 0 0 0 0 0 0 

Fe 

g/day 

Mn 

g/day 

Al 

g/day 

AOX 

g/day 

114


7.3 Existing Technical Measures to Reduce Pollution 

Loading 

In general, there is no technical means currently imposed to reduce pollutant 

load, for households. Most households discharge greywater directly to the 

stormwater drains and probably the only measure to reduce contaminants from 

entering the drains is the usage of coarse filtering equipment or apparatus installed 

at their washing sinks or wash basins. 

Houses are generally equipped with septic tanks for treatment of blackwater, 

but they are not well functioning due to inadequate desludging. A programme, 

however, was launched to enforce the Rule of “Compulsory desludging of septic 

tanks, 1988” gazetted 15 th October 1998, which specifies that every septic 

tank in the city must be desludged every second year. 

However, it must be stressed that even if all septic tanks in Kuching were 

desludged regularly and functioning properly, the effect in terms of reducing 

the pollution load to the tributaries and main river will still be insignificant. 

Consequently, the sewage from the houses does not comply with the standards 

as stipulated in the Environmental Quality (Sewage and Industrial Effluents) 

Regulation, 1979. 

Most of the food outlets also discharge wastewater directly to the drains. Some 

of them do have treatment measures for physical filtration and removal of 

heavy oil and grease residue (grease traps) in place. However, the grease traps 

are generally not functioning, because they are not emptied and even in the case 

they are actually emptied, it seems that this generally takes place in the drain 

downstream of the trap. 

At present, information on the numbers of food outlets with treatment facilities 

is not available. 

In general, the sewage from food outlets does not comply with the standards as 

stipulated in the Environmental Quality (Sewage and Industrial Eeffluents) 

Regulation, 1979. 

Many industries have their wastewater treatment system in place. However, 

there are a few industries without any wastewater treatment. Presently, data on 

the number of industries with and without proper wastewater treatment ssystem 

is not available. 

In the SUD field study, it was generally observed that the industries equipped 

with proper treatment facilities complied with the regulations, whereas those 

without or with inadequate facilities did not. 


115


7.4 Existing Control and Enforcement Measures 

The enforcement measures are generally passive, i.e. only in case of complaints, 

authorities carry out inspections and may impose a fine to the offender. 

There is currently no specific active enforcement measure carried out by the 

authorities to control the discharge of sewage from households and/or food outlets. 

Other than cleanliness campaigns and awareness programmes, no direct 

inspection or regular checks on the discharge has been made. 

The Department of Environment (DOE) is monitoring the wastewater from a 

small fraction of the industries in Kuching for compliance to the Environmental 

Quality Act 1974 (EQA). The monitored industries include: industries discharging 

more than 60 m 3 wastewater per day or where the total load of BOD 

in effluents exceed 6 kg per day, industries involved in processing of oil palm 

fruit and industries involved in the processing of rubber. 

NREB is regulating the outlets from pig farms and other livestock activities. 

7.5 Assessment of Preliminary Indicators 

One of the important objectives of the river quality baseline study has been to 

assess the suitability of the selected preliminary indicators for river quality in 

the EMS for Kuching. 

The baseline study has indicated that: 

Some of the selected preliminary indicators are not suitable as indicators; 

Some of the preliminary indicators should be modified; amd 

Some new indicators should be added. 

The proposed modifications of the preliminary indicators and the rationale for 

the modifications are presented in the following. 

7.5.1 State Indicators 


Preliminary indicators proposed not to be included in the EMS 

The baseline study has clearly showed that concentrations of heavy metals in 

surface water are not suitable as indicators for water quality of the river. 

The levels of the heavy metals Hg, Pd, As, Zn, Cd, Cr, Cu and Ni in water 

measured in NREBs‟ water quality monitoring of the Sg. Sarawak system are 

generally very low and below the detection limits even in the very polluted 

tributaries. It is a worldwide experience, that dissolved heavy metals are generally 

encountered in very low levels in surface water and that analytical detection 

limits are sometimes higher than natural levels. The reason for the low lev- 


116


els of dissolved heavy metals in even very polluted areas is that most trace elements 

are readily adsorbed onto particulate matter, which is subject to sedimentation. 

Data on heavy metals in sediments are therefore, more suitable as indicators 

because discharged metals are accumulated in the sediments (Cf. below). 

The general low levels of dissolved trace elements also make it very difficult to 

measure concentrations correctly, as there is a high risk of contamination during 

sampling, pre-treatment and storage. Therefore, there is a high risk that an 

observed increase in concentration between two sampling rounds may be due to 

a slight contamination of the sample and not a real increase. 

The same problems may be encountered for PAHs and Total Petroleum Hydrocarbons. 

The levels of Fe and Mn in water measured in NREBs‟ water quality monitoring 

of the Sg. Sarawak system are generally very high also in areas not affected 

by human activities. 

The high iron and manganese concentrations are due to natural processes and 

not primarily a result of human activities, although discharge of wastewater 

may contribute to increased levels. Results from 1999 indicates that the concentrations 

of iron in Sg. Sarawak Kiri are at the same level as those encountered 

in the heavily polluted Sg. Maong and higher than the levels in Sg. Sarawak 

main fronting Kuching. 

High background concentrations in surface water are common in natural waters. 

Leaching of iron is particularly significant in swampy areas such as freshwater 

swamps, nipah forests and mangroves, which are abundant in the Sg. Sarawak 

catchment area. The soils in such areas are waterlogged and anaerobic. 

In the anaerobic, waterlogged soil, the solubility of iron increases. Insoluble 

Fe +++ is reduced to soluble Fe ++ , which is then transported via groundwater to 

the river. The solubility of manganese increases in anaerobic swampy area in 

the same way as iron does. 

Occurrences of Fe and Mn in ground and surface waters are very much dependent 

on environmental conditions, especially oxidation and reduction have resulted 

in that Fe and Mn are not included in many priority lists or water quality 

standards, internationally. 

Based on the above considerations, it is therefore proposed that the following 

preliminary indicators for surface water quality are not to be included in the 

EMS for Kuching: Hg, Pd, As, Zn, Cd, Cr, Cu, Ni, Fe, Mn, Polyaromatic hydrocarbons 

(PAH) and total petroleum hydrocarbons (TPH). 


117


Indicators proposed to be included in the EMS 

The baseline study has confirmed that the following preliminary indicators for 

water quality are suitable and are therefore proposed to be included in the EMS 

for river quality: 

pH, DO; 

BOD, COD, TSS; 

Nutrients (Ammoniacal Nitrogen (NH4-N), Nitrates, Phosphorous); and 

Bacteria (Faecal coliforms and total coliforms). 

Sediment quality 


As outlined above, Fe and Mn are not suitable as indicators for the river quality 

because natural processes may result in the discharge of very large quantities of 

Fe and Mn not associated with human activities. These two metals finally end 

up in the sediment. It is therefore, proposed that Fe and Mn are not included in 

the indicators for sediment quality. 


The baseline study has confirmed that the following preliminary indicators for 

sediment quality are suitable and are therefore, proposed to be included in the 

EMS for river quality: 

Nutrients (Ammoniacal Nitrogen (NH4-N), Nitrates); 

Heavy metals (Hg, Pb, AS, Zn, Cd, Cr, Cu, Ni); 

CN; and 

Oil and grease, Polyaromatic Hydrocarbons, PAH, Total Petroleum Hydrocarbons 

(TPH). 

In the preliminary indictors, phosphorous is included. However, the type of 

phosphorous is not specified. It is proposed that Tot P is measured (Cf. below). 

It is further proposed to add the following parameters, which were not proposed 

during the selection of preliminary indicators: 

Loss on ignition; and 

Total N. 


118


The reason for proposing these parameters is than the baseline study has indicated 

that one of the major pollution problems of Sg. Sarawak is the discharge 

of organic matter. Loss on ignition is a measure of the organic matter content of 

the sediment. Total N and Total P are measures of all forms of N and P found 

in the sediment, including that incorporated in dead organic matter, irrespective 

of the chemical form (ammonium, nitrate, etc) which is highly dependent on 

redox processes in the sediment as well as biological activity. 

Pollutants in aquatic organisms 

The most suitable organisms for monitoring purposes are molluscs. The baseline 

study has indicated that it may be difficult or impossible to collect sufficient 

amounts of molluscs for monitoring in Sg. Sarawak and the tributaries in 

Kuching. However, molluscs transplanted in cages can be used. 


It is proposed that transplanted mollucs be measured in their tissues for the 

concentration of the following polutants: 

Heavy metals (Hg, Pb, As, Zn, Cd, Cr, Cu, Ni and organotin); and 

Polyaromatic Hydrocarbons, PAH, Total petroleum hydrocarbons (TPH). 

The feasibility of this approach must be assessed from a pilot study. 

Ecological parameters 

Diversity index, species of fish of yy family and species of invertebrates of zz 

family have been chosen as preliminary indicators. 


It is proposed not to use “Invertebrates of zz family” as indicators because even 

in the unpolluted state the part of Sg. Sarawak running through Kuching will 

not house the families of invertebrates which are clear indicators of the unpolluted 

state. These families are typically encountered further upstream of the 

river system where the river is narrower and flowing faster. 


It is proposed to apply the Pearson and Rosenberg 1978 method of assessment 

of pollution impacts on benthos in which number of species and abundance (no 

individuals/m²) and species composition to be used as indicators. This method 

has been used in the baseline study (described in detail in Volume 3). 

It is proposed that the diversity of benthic macroinvertebrates be used as indicator 

(Shannon Wiener diversity index). 

It is proposed that catch per unit effort (cpu) of all fish and prawn species in a 

catch to be used as indicators. Catch per unit effort is a standard measure of effort 

(including fishing time, length of net etc, dependent on fishing method). 


119


Cpu of giant prawn (Macrobrachium rosenbergii) and the fish species Mystus 

spp. and Oxyeleotris marmorata are also proposed as indicators. These species 

are the commercially most significant species in Sg. Sarawak. 

Aeasthetics 

The preliminary indicators chosen are proposed to be included in the EMS. i.e. 

Estimated volume of floatables collected from Sg. Sarawak; and 

Level of smell by using standard method. 

The baseline study has shown that the internationally recognised standard 

method using the Threshold Odour Number is a good method. 

In addition, the number of complaints of smell in river, drains and tributaries 

should be used as indicators as well. 

7.5.2 Load Indicators 

It is proposed that all preliminary load indicators be used in the EMS. In addition, 

it is proposed that estimates of loads from households, food outlets and 

industries to be used applying the methods used in the baseline study. 


120


8 References 

Abott, R.T. (1991). Seashells of Southeast Asia.m Graham Brash, Singapore. 

145pp 

Anon. (2000). Information on Food Premises (Fast Food, Restoran, Coffee 

Shops, Seafood, Bakery & Cold Storage). Compiled and faxed by Dewan Bandaraya 

Kuching Utara (DBKU). Sarawak 

Anon. (2000). List of Pig Farming located at Sungai Sarawak Catchment Area. 

Compiled by the Livestock Unit, Natural Resources and Environment Board. 

Sarawak 

Anon. (2000). Number of the Different Types of Premises and the Type of 

Sewage System Used in MBKS Areas. Compiled by Kuching City South 

Council (MBKS) 2000. Sarawak 

Anon. (2000). Number of the Different Types of Premises. Compiled by 

Kuching City South Council (MBKS) 2000. Sarawak 

Anon. (2000). Penyataan Senarai Kes Kompaun Bagi Kebersihan Sungai 

(Cleanliness) Di Wilayah 1, Kuching. Compiled and faxed on 11 December 

2000 by Sarawak Rivers Board (SRB). Sarawak 

Anon. (2000). Raw Water Quality Report for Various Locations along Sg. Sarawak 

Kiri for the year of 1998, 1999 & 2000 (up to Oct). Compiled by 

Kuching Water Board (KWB). Sarawak 

Anon. (2000). Result of Chemical Analysis of Bacteriological Samples for 

Siniawan Water Supply Authority in Kuching Division from 1992 – 2000. 

Compiled by Public Works Department HQ. Faxed on 27 November 2000 

Anon. (2000). Result of Chemical Analysis of Chemical Samples for Siniawan 

Water Supply Authority in Kuching Division from 1990 – 2000. Compiled by 

Kuching Water Board (KWB) 

Anon. (2000). Water Consumption Statistic for the year 1998, 1999 & 2000 (up 

to Oct.) 


121


Anton, A. (2000). Bioindicators in river quality management. Proceedings for 

the Environmental Indicators Seminar for River Water Quality and Waste 

Management. Sarawak Government/Danced Sustainable Urban Development 

Project. Pg 39-47 

Canfield T. J, N.E. Kemble, W.G. Brumbaugh, F.J. Dwyer, C.G. Ingersoll and 

J.F. Fairchild (1994). Use of benthic invertebrate community structure and the 

sediment quality triad to evaluate metal contaminated sediment in the upper 

Clark Fork River, Montana. Environmental Toxicology and Chemistry 13: 

1999-2012 

Canfield, T.J. F.J. Dwyer, J.F. Fairchild, P.S. Haverland, C.G. Ingersoll, N.E 

Kemble, D.R. Mount, T.W. La Point, G.A. Burton and M.C. Swift (1996). Assessing 

contamination in great lakes sediments using benthic invertebrate 

communities and the sediment quality triad approach. Journal of Great Lakes 

Rea. 22: 565-583 

CCME. Canadian Council of Ministers of the Environment (1999). Canadian 

sediment quality guidelines for the protection of aquatic life. Summary Tables. 

In: Canadian environmental quality guidelines, 1999, Canadian Council of 

Ministers of the Environment, Winnipeg 

Chemsain and Perunding Utama. (1996). Preliminary Environmental Impact 

Assessment Report for Proposed Steelmill at Kampung Goebilt, Jalan Bako, 

Kuching, Sarawak. Steel Industry Sarawak Sdn. Bhd. Sarawak 

Chemsain. (1997). EIA for Proposed Borneo Heights Road Project. Borneo 

Heights Sdn. Bhd. Sarawak 

Chemsain. (1997). Preliminary EIA on the Proposed Kuching Riverfront Development 

Project, Kuching, Sarawak. Kuching Riverfront Sdn. Bhd. Sarawak 

Chemsain. (1998). Treated – Effluent Monitoring Report. Kuching City South 

Council (MBKS). Sarawak 

Chemsain. (1998). EMP for the Proposed Medium-Low Cost Housing Project, 

Matang Road, Kuching. Ko-Perkasa Berhad. Sarawak 

Chemsain. (1998). EMP: Proposed Sand Extraction at Sungai Sarawak. Sublanco 

Enterprise Sdn. Bhd. Sarawak 

Chemsain. (1998). Preliminary EIA for the Proposed Low Cost Housing at 

Kota Samarahan, Samarahan Division. Custodev Tiga Sdn. Bhd. Sarawak 

Chemsain. (1998). Preliminary EIA for the Proposed Quarry Operation at Bukit 

Udur, Siburan, Sarawak. Sara Kuari Sdn. Bhd. Sarawak 

Chemsain. (1998). Preliminary EIA on the Proposed Beverly Garden Development, 

Mile 13, Kuching - Serian Road, Kuching Division. Pui Nam Cheong 

Sdn. Bhd. Sarawak 


122


Chemsain. (1998). Preliminary EIA on the Proposed Low-Medium Cost Housing 

at Taman Malihah, Kuching. Sarawak Housing & Development Commission 

& CDM Resources Sdn. Bhd. Sarawak 

Chemsain. (1999). EIA for the Integrated Fishing Development Aquaculture 

Project. ASSAR Fishery Sdn. Bhd. Sarawak 

Chemsain. (1999). Preliminary EIA on Proposed Low Cost Housing Project 

(Taman Mutiara) at Jalan Jambusan, Bau, Kuching Division. San Chin Realty 

Sdn. Bhd. Sarawak 

Chemsain. (1999). Preliminary EIA on the Residential Development Sama Jaya 

Selatan, Kuching, Sarawak. Ibraco Realty Development Sdn. Bhd. Sarawak 

Chemsain. (1999). Water Quality Monitoring at Sungai Bintangor & Sungai 

Padungan. Drainage and Irrigation Department. Sarawak 

Chemsain. (2000). EIA on Proposed Low Medium Cost Housing at Mile 13, 

Kuching-Serian Road, Kuching Division. Rastar Development Sdn. Bhd. Sarawak 

Chapman D (1997).Water quality assessments. Published on behalf of 

UNESCO, WHO, UNEP. E&F Spon. London and New York 

Concept P Associates and Chemsain. (1999). EMP for the Proposed Mixed Development 

at Muara Tabuan, Lot 9291, Block 11, Muara Tebas Land District, 

Kuching Division, Sarawak. Astro Harta Sdn. Bhd. Sarawak 

ECOSOL. (1998). Preliminary EIA for the Proposed Institut Latihan Perindustrian 

(ILP) Sarawak In Samarahan Division. Jabatan Tenaga Rakyat. Sarawak 

Jurutera CMP. (1998). Preliminary EIA Report for the Development of the Yen 

Yen Park Project. IJM Properties Sdn. Bhd. Sarawak 

Jurutera CMP. (1998). Preliminary EIA Report for the Proposed Taman Sri 

Matang. Hwa Kwang Development Sdn. Bhd. Sarawak 

Jurutera CMP. (1999). Preliminary EIA Report for Proposed Taman Desa 

Moyang on Lots 40, 483 and 597 along Tondong-Batu Kawa, Road, Kuching. 

Jong Kui Ling Construction Sdn. Bhd. Sarawak 

Jurutera CMP.(1998). Preliminary EIA for The Proposed Development of Sarmax 

Park. Sarmax Sdn. Bhd. Sarawak 

Jurutera Jasa. (1994). Hydrological Study of the Sungai Sarawak Kiri Catchment 

and Feasibility Study of a proposed “Submersible Weir” across Sungai 

Sarawak Kiri. Kuching Water Board. Sarawak 


123


KBM. (2000). Water Quality Monitoring Year 1998, 1999 and Oct 2000 for 

Operation of Sungai Sarawak Barrage. Kuching Barrage Management, Sarawak 

Pearson T.H & R. Rosenberg (1978). Macrobenthic succession in relation to 

organic enrichment and pollution of the marine environment. Oceanogr. Mar. 

Biol. Ann. Rev. 16, 229-311 

Sarona Sdn. Bhd. (1998). Preliminary EIA Study for Second Kuchng Bridge 

Project. Zalpoint Corporation Sdn. Bhd. Sarawak 

KTA. (1997). Sungai Sarawak Environmental Control & River Management 

Study: Final Report. Volume 2: River Management Plan. Natural Resources 

and Environment Board and Drainage and Irrigation Department. Sarawak 

KTA. (1997). Sungai Sarawak Regulation Scheme: Environmental Monitoring 

Progress Report No. 4. Public Works Department (JKR). Sarawak 

L. K., Wong. (1998). Physical and Chemical Characteristics of the Sediment 

from Sungai Maong. Faculty of Resource Science and Technology, UNIMAS. 

Sarawak 

Lau, S., Murtedza, M. and Sabtuyah, S. (1995). Profile of Heavy Metal in Water 

and Bottom Sediment of Sg. Sarawak. Paper presented at Malaysian Chemical 

Congress ‟95, (13-16 Nov., 1995). Kuching, Sarawak 

Lau, S., Murtedza, M. and Sabtuyah, S. (1996). Logam Berat di dalam Sedimen 

sebagai Penyurih kepada Punca Pencemaran di Sungai Sarawak. Malaysian J. 

Analytical Sciences, 2: No. 2. pp. 365-371 

Lau, S., Murtedza., Tan., C.Y.T and Sabtuyah, S. (1998). Accumulation of 

Heavy Metals in Freshwater Molluscs. The Science of the Total Environment 

214 (1998) 113-121. Elsevier. Pp. 115-121 

Lau, S., Pereira, T.J., Wong, L.K. and Chai, A. (1998). The Study of Sediment 

and Water Qualities of Sg. Maong, Sarawak. Proceeding Malaysian Chemical 

Congress „98 

Lau, S., Seti, S. and Tosilzan, A.G. (2000). Impacts of Urbanisation on Water 

Quality: A Case Study on Sg. Tabuan, Kuching, Sarawak. Paper presented at 

the Malaysian Chemical Congress 2000, 16-18 October 2000, Ipoh, Perak, Malaysia 

Maieform (Sarawak). (1998). Integrated Waste Management for Kuching. 

Presentation of the Inception Reports 26th of May 1998. State Planning Unit, 

Sarawak 

Meteorological Services Department, Kuching (2000). Meteorological Records 

from monitoring station at Kuching International Airport operated and main- 


124


tained by the Perkhidmatan Kajicuaca (Meteorological Services Department) 

Malaysia, Cawangan Sarawak 

Memon A & M. Murtedza(1999). Water Resource Management in Sarawak, 

Malaysia. CTTC University Malaysia Sarawak. 

MEX Environmental. (1997). Preliminary EIA Report for the Proposed 

Kuching Central Prison Project. WMM Holdings Sdn. Bhd. Sarawak 

Mex Environmental. (1998). Preliminary EIA for the Proposed BDC - Matang 

Township. Borneo Development Corporation (S) Sdn. Bhd. Sarawak 

Mex Environmental. (1998). Preliminary EIA Report for the Proposed Mixed- 

Development Project on Lot 8, Block 26, Muara Tuang Land District, Kota 

Samarahan. Bodco Engineering & Construction Sdn. Bhd. Sarawak 

Mex Environmental. (1999). EIA Study for the Proposed Memorial Park Development 

on Lot 431 (BOT 3776) and Lot 395 (BOT 1856), Senggi-Poak 

Land District, Bau-Kuching Road, Bau. Nir-Warna (Kuching) Sdn. Bhd. Sarawak 

Mohamad Ariffin. (1998). Heavy Metal Contents in Aquatic Organisms from 

the Estuary of Sungai Sarawak. Faculty of Resource Science and Technology, 

UNIMAS. Sarawak 

NREB. (2000). River Watch Programme: Water Quality Data for Southern Region 

: Sg. Sarawak for Year 1999. Compiled by Water Quality and Laboratory 

Unit, Natural Resources and Environment Board, Sarawak 

NREB (2000). River Watch Programme: Water Quality Data for Southern Region 

: Sg. Sarawak for Year 2000. Compiled by Water Quality and Laboratory 

Unit, Natural Resources and Environment Board, Sarawak 

Palanisamy s/o T. Kuppusamy (1999). Heavy Metal Distribution in the Coastal 

Sediments of Kuching Bay. Faculty of Resource Science and Technology, 

UNIMAS. Sarawak 

PCM Consultant. (1999). Preliminary EIA on the Proposed Deepening of 

Navigation Channel for Senari Deep Water Port. Kuching Port Authority. Sarawak 

Pearson T.H & R. Rosenberg (1978). Macrobenthic succession in relation to 

organic enrichment and pollution of the marine environment. Oceanogr. Mar. 

Biol. Ann. Rev. 16, 229-311 

Perunding EC Sepakat. (1999). EIA for the Proposed Taman BDC Stakan on 

Lots 257-264, 294-296, 302-306, 313, 314, 321-321-325, 335, 336 and 2174, 

Block 24, Muara Tuang Land District, Samarahan Division, Sarawak. Borneo 

Development Corporation (S) Sdn. Bhd. Sarawak 


125


Sarona. (1997). EIA for the Proposed Integrated Police Training School, 

Kuching, Sarawak. Ministry of Home Affairs. Malaysia 

SPU (1998). State of Sarawak State Planning Unit. Integrated Waste „Management 

System for Kuching. Inception report Wastewater May 98. Maierform 

(Sarawak) Sdn. Bhd. 

University of Malaya et al. (1992). Development of Water Quality Criteria & 

Standards – Phase IV (River Classification): Draft Final Report. Volume X: 

River Classification – Sg. Sarawak. Department of Environment. Ministry of 

Science, Technology and Environment. Government of Malaysia 

UP Services. (1997). EIA Report for the Sama Jaya Free Industrial Zone 

Kuching, Sarawak. Ministry of Industrial Development. Sarawak 

Wong, J. J., Zani Assim and et al. (2000). Development of Analytical Methods 

for Bultytins (TBT & DBT) Determination in Water and Sediment Samples 

from Sarawak River. Paper presented at the Malaysian Chemical Congress 

2000, 16-18 October 2000, Ipoh, Perak, Malaysia 


126


APPENDIX 1 

WATER QUALITY DATA 


127


Table 1. Water quality parameters Zone A (Sg. Sarawak Kanan) 1999. Mean of three sampling sites. Wet season: Nov-Feb. Dry season: 

Mar-Oct. 

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Mean Mean 

Parameter Wet Wet Dry Dry Dry Dry Dry Dry Dry Dry Wet Wet Wet Dry 

No. of Samples Analysed 3 3 3 3 3 3 3 3 3 3 3 3 3 3 

pH Value - 6,9 6,9 7,0 7,1 6,9 7,2 6,9 6,8 6,9 7,0 

Dissolved Oxygen mg/kg - 5,4 4,3 3,0 3,8 4,9 7,2 5,9 6,2 6,0 4,8 

Biochemical Oxygen Demand mg/kg -


Table 2. Water quality parameters Zone A (Sg. Sarawak Kanan) 2000. Mean of three sampling sites. Wet season: Nov-Feb. Dry 

season: Mar-Oct. 

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Average Average 



pH Value 6,7 6,3 7,2 7,2 6,8 6,9 6,8 6,9 6,5 7,0 

Dissolved Oxygen mg/kg 7,3 3,8 6,8 7,3 7,5 7,4 3,9 3,9 6,0 6,1 

Biochemical Oxygen Demand mg/kg 0,4 0,3 0,2 1,3 0,3 0,4 0,6 0,6 0,52 0,6 

Chemical Oxygen Demand mg/kg 7,3 5,5 4,6 10,9 3,5 4,7 9,5 8,4 6,78 6,9 

Total Suspended Solids mg/kg 43,0 69,7 3,7 26,0 18,3 20,1 1,5 9,3 24,0 13,2 

Ammoniacal Nitrogen mg/kg 0,05 0,05 0,20 0,10 0,05 0,05 0,10 0,1 0,08 0,1 

Faecal Coliform Count (MPN/100mL) 1367 6333 800 6867 16000 7300 1067 7133 3850 6528 

Total Colifom Count (MPN/100mL) 6333 13667 1367 11667 16000 16000 3000 8000 9504 9339 


129


Table 3. Water quality parameters Zone B (Sg. Sarawak Kiri) 1999. Mean of two sampling sites. Wet season: Nov-Feb. Dry season: 

Mar-Oct. 




pH Value 7,0 7,1 6,7 6,9 7,1 7,1 6,9 7,1 7,3 7,1 6,9 6,7 6,9 7,0 

Dissolved Oxygen mg/kg 3,5 3,7 2,8 2,6 4,5 2,9 1,9 9,6 - 7,4 7,1 6,9 5,3 4,5 

Biochemical Oxygen Demand mg/kg


Table 4. Water quality parameters Zone B (Sg. Sarawak Kiri) 2000. Mean of two sampling sites. Wet season: Nov-Feb. Dry season: 

Mar-Oct. 




pH Value 6,9 6,7 7,2 7,1 7,0 6,9 7,0 7,0 6,8 7,0 






Nitrate mg/kg


Table 5. Water quality parameters Zone C (main Sg. Sarawak from Batu Kawa bridge to upstream of Satok bridge) 1999. Mean of 

two sampling sites. Wet season: Nov-Feb. Dry season: Mar-Oct. 



No. of Samples Analysed 2 2 2 2 2 2 2 2 2 2 2 

pH Value 7,1 7,1 6,7 7 7,1 7,2 7,2 6,9 7,4 6,8 6,9 6,8 7,0 7,0 



Table 6. Water quality parameters Zone C (main Sg. Sarawak from Batu Kawa bridge to upstream of Satok bridge) 2000. Mean of 

two sampling sites. Wet season: Nov-Feb. Dry season: Mar-Oct. 



No. of Samples Analysed 2 2 2 2 2 2 2 2 2 2 2 

pH Value 6,7 6,9 6,9 6,9 6,7 6,9 6,9 6,9 7,1 6,9 6,8 6,9 



Table 7. Water quality parameters Zone D (main Sg. Sarawak from Satok bridge to downstream of barrage) 1999. Mean of five/six 

sampling sites. Wet season: Nov-Feb. Dry season: Mar-Oct. 



No. of Samples Analysed 5 5 5 5 5 6 6 6 6 6 6 6 

pH Value 6,8 6,6 6,7 7,0 7,2 7,0 7,3 7,0 7,0 7,1 6,8 6,7 7,0 

Dissolved Oxygen mg/kg 3,1 5,2 5,0 3,0 2,5 3,8 2,6 6,4 4,3 5,6 4,6 4,3 4,1 

Biochemical Oxygen Demand mg/kg 1,0 2,0 3,1 1,1 1,3 0,7 1,3 1,5 0,7 0,4 0,2 1,1 1,2 

Chemical Oxygen Demand mg/kg 14,5 12,4 12,4 10,6 27,7 22,3 24,9 5,4 8,3 7,0 5,3 10,7 14,8 

Total Suspended Solids mg/kg 16,0 12,1 29,6 16,0 10,9 18,7 21,2 33,7 61,7 30,8 47,7 25,3 27,8 

Ammoniacal Nitrogen mg/kg 2,56 0,11 0,16 11,2 0,10 0,08 0,13 0,17 0,17 0,16 0,10 0,9 1,5 

Nitrate mg/kg


Table 8. Water quality parameters Zone D (main Sg. Sarawak from Satok bridge to downstream of barrage) 2000. Mean of five/six 

sampling sites. Wet season: Nov-Feb. Dry season: Mar-Oct. 




pH Value 6,5 6,4 7,0 7,0 6,9 7,0 7,0 6,7 6,5 6,9 






Nitrate mg/kg 0,20 0,06 0,16 0,18 0,21 0,21 0,39 0,33 0,1 0,2 

Phosphorus mg/kg 0,23 0,12 0,12 0,13 0,16 0,20 0,34 0,10 0,2 0,2 

Mercury mg/kg


Table 9. Water quality parameters Zone E (Sg. Maong) 1999. Mean of four sampling sites. Wet season: Nov-Feb. Dry season: Mar- 

Oct. 




pH Value 6,9 7,2 6,9 6,7 7,0 7,1 7,1 7,1 7,0 7,0 6,5 6,9 7,0 

Dissolved Oxygen mg/kg 0,6 0,6 0,4 0,7 0,5 0,1 0,8 1,5 2,3 4,8 2,5 1,3 1,4 

Biochemical Oxygen Demand mg/kg 13,1 13,6 11,1 7,9 11,0 36,5 11,3 8,5 6,6 2,5 2,0 9,6 11,9 

Chemical Oxygen Demand mg/kg 32,5 40,6 28,4 24,1 37,9 49,3 43,5 62,5 28,0 26,1 32,4 35,2 37,5 

Total Suspended Solids mg/kg 21,3 17,6 17,6 17,5 12,3 19,8 7,6 17,3 14,0 34,3 7,8 15,6 17,5 

Ammoniacal Nitrogen mg/kg 0,98 4,67 2,06 1,14 3,19 7,74 5,85 9,83 6,20 0,45 0,92 2,2 4,6 

Nitrate mg/kg


Table 10. Water quality parameters Zone E (Sg. Maong) 2000. Mean of four sampling sites. Wet season: Nov-Feb. Dry season: 

Mar-Oct. 



No. of Samples Analysed 4 4 4 4 4 4 4 4 4 4 4 4 4 

pH Value - 6,6 7,0 6,9 7,1 7,0 6,9 6,7 6,6 6,9 

Dissolved Oxygen - 2,6 0,3 2,7 0,5 0,3 0,7 0,4 2,6 0,8 

Biochemical Oxygen Demand - 3,6 6,8 1,6 9,4 4,0 5,9 8,5 3,6 6,0 

Chemical Oxygen Demand - 27,0 28,4 21,6 40,6 37,2 37,1 28,9 27,0 32,3 

Total Suspended Solids - 12,0 23,0 28,3 25,0 31,5 33,0 26,0 12,0 27,8 

Ammoniacal Nitrogen - 1,99 8,05 0,05 6,37 3,57 3,75 6,38 2,0 4,7 

Nitrate -

River Quality Baseline Study. Vol. 1 138 

APPENDIX 2 

AN OVERVIEW OF THE STATE ADMINISTRATION 

TYT YANG DI-PERTUA NEGERI 

LEGISLATIVE EXECUTIVE JUDICIARY 

SPEAKER CHIEF MINISTER BORNEO HIGH COURT 

DEWAN UNDANGAN CABINET (MMKN) SESSION COURT 

CHIEF MINISTER'S DEPARTMENT MAGISTRATE COURT 

MINISTRIES 

1 Ministry of Planning & Resource Management 

2 Ministry of Finance and Public Utilities 

3 Ministry of Rural and Land Development 

4 Ministry of Environment and Public Health 

5 Ministry of Tourism 

6 Ministry of Housing 

7 Ministry of Industrial Development 

8 Ministry of Agriculture and Food Industry 

9 Ministry of Social Development & Urbanisation 

10 Ministry of Infrastructure Development 

& Communications 

1. Chief Minister’s Department 

State Planning Unit (SPU) 

Kuching City North Hall (DBKU) 

2. Ministry of Planning and Resources Management 

Land and Survey Department 

Forest Department 

3. Ministry of Finance and Public Utilities 

Water Authority 

Water Boards (Water Supply) 

4. Ministry of Rural and Land Development 

Drainage and Irrigation Department (DID) 

5. Ministry of Environment and Public Health (MOEPH) 

Kuching City South Council (MBKS) 

Padawan Municipal Council (MPP) 

District Councils (Bau, Samarahan, Serian) 

State Health Department 


6. Ministry of Industrial Development 


ADAT COURT


7. Ministry of Agriculture and Food Industry 

Department of Agriculture 

8. Ministry of Infrastructure Development and Communication 

Public Works Department (JKR) – the Water Resources Division 

Kuching Port Authority 

Sarawak Rivers Board (SBR) 

9. Minsitry of Tourism 

10. Minsityr of Housing 

11. Ministry of Social Development & Urbanisation 

12. Other Relevant Committees and Councils 

State Planning Authority 

Water Resources Council 

C:\Documents and Settings\user\Desktop\SUD-02-25 - River quality baseline study Vol.1 by Erling\final\River Quality Baseline main report.doc


APPENDIX 3 

A SUMMARY OF RELEVANT ACTIVITIES AND MANDATES 

Name of Agency Relevant activities Relevant regulation 

State Planning Unit Overall economic planning. 

Infrastructure projects 

including waste and 

wastewater projects 

State Planning Author- Approval of develop- 

ity 

Water Resources 

Council 

ment projects 

Policy and programmes 

for conservation, management 

and use of water 

resources 

Water Authority Water supply. 

Identification of water 

catchments, control of 

contamination and pollution 

of water or sources 

of water supply, licenses 

Land and Survey Department 

Drainage and Irrigation 

Department 

State Health Department 

Local Authorities 

Natural Resources and 

Environment Board 

for water abstraction 

Agency for landuse (e.g. 

sand extraction from rivers 

and utilization of river 

banks), land classification 

and development – 

Secretariat to the SPA 

Irrigation and drainage 

works, river engineering, 

flood mitigation, hydrol- 

ogy, data collection, 

License of businesses, 

discharge from hospitals 

and certain food outlets 

Approval of building 

plans 

Construction and maintenance 

of public drains 

Sewage treatment 

Collection and disposal 

of waste 

License of businesses 

Operation of markets 

Nuisances 

Broad powers within policy 

making, coordination 

and monitoring. Pollution 

control powers e.g. EIA, 


WO 4 

WO 8 and 17 

No regulation 

PHO 

21, 25, 33, and 38 

LAO 

104, 105, 112, 132, 

134, 136, 138 

Entire LAC in particular 

9-17, 18- 20, 41, 44- 

50 

NREO 

5, 10, 11, 18 and 30 

and subsidiary rules 

under these provi-


Ministry of Industrial 

Development 

Department of Agriculture 

State Veterinary 

Health Department 

Public Works Department 

The Water Resources 

Division 

environmental management 

systems and issu- 

ance of rules and orders. 

License for industrial activities 

(in Industrial Es- 

tates) 

Soil conservation 

Drainage and irrigation 

Crop water requirement 

Pollution from non-point 

sources 

License of aquaculture 

License of businesses 

(lifestock rearing, meat 

processing) 

Responsible for infrastructure 

development for 

water supply and sewerage 

- Secretariat to The 

Water Authority and the 

Water Resources Council 

advising the Minister on 

water resources issues 

and identification of water 

catchment areas 

Sarawak Rivers Board Regulate river traffic – 

power to prohibit discharge 

to gazetted rivers 

from public and private 

sources and regulate activities 

in the rivers and 

on the banks of gazetted 

Kuching Port Authority 

Department of Environment 

(Federal Agency) 

rivers 

Provide port facility 

Broad powers within national 

policy making, 

monitoring and coordination. 

Pollution control 

powers e.g. EIA, licensing 

of industry, standard 

setting 


sions 

Only licenses for 

operation 

SIFR 6 

VPHO 

7, 22, 29, 42, 44, 69, 

102 

SRO 

4, 9, 12, 13, 16,17, 

20, 33, 38 

SRCR 

3, 6, 8, 10, 12, 15, 

17, 12, 22 

EQA 

3, 11, 12, 18, 21 and 

32 

EQA Sewage Regulation 

4, 6, 8, 11

Here - Eco-Ideal Consulting Sdn Bhd

Create successful ePaper yourself

Delete template?

Save as template?